OBJECTIVE:

To evaluate the potential link between systemic inflammation and impaired lung function in people with ataxia-telangiectasia (A-T), we hypothesized that serum levels of interleukin (IL)-6, a proinflammatory cytokine, would correlate inversely with lung function in subjects with A-T.

STUDY DESIGN:

Consecutive subjects with A-T were recruited from the Johns Hopkins Outpatient A-T Clinical Center. Serum levels of IL-6 and 8 were measured by enzyme-linked immunosorbent assay. Spirometry was performed in subjects ≥ 6 years of age on the same day that serum was obtained for measurements of cytokines.

RESULTS:

Approximately 80% of subjects had elevated serum IL-6 levels (> 1.0 pg/mL). No association was found between elevated IL-6 and age. Elevated IL-8 levels were found in 23.6% of subjects, and all subjects with elevated IL-8 levels had elevated IL-6 levels. Subjects with elevated IL-6 levels (mean: 6.14 ± 7.47 pg/mL) had significantly lower mean percent forced vital capacity (FVC%, 50.5% ± 17.8%) compared with subjects with normal serum IL-6 levels(FVC% of 66.2 ± 16.1, P = .018). Greater IL-6 levels were associated with lower FVC% even after adjustment for receiving gamma globulin therapy (P = .024) and supplemental nutrition (P = .055).

CONCLUSIONS:

An association was found between elevated serum IL-6 levels and lower lung function in subjects with A-T. In addition, subjects with both elevated IL-6 and IL-8 had the lowest mean lung function. These findings indicate that markers for systemic inflammation may be useful in identifying individuals with A-T at increased risk for lower lung function and may help in assessing response to therapy.

Copyright © 2016 Elsevier Inc. All rights reserved.

BACKGROUND AND AIMS:

Evaluate the nutritional status, plasma concentration of vitamin E and markers of cardiovascular risk in ataxia telangiectasia (AT) patients.

METHODS:

Cross-sectional study with 13 patients with AT and 22 healthy controls, evaluating the following factors: nutritional status, food intake, lipid profile, plasma concentration of vitamin E, malondialdehyde and high sensitivity C-reactive protein, linking them with atherosclerosis risk in AT patients.

RESULTS:

Average age was 14.6 in the AT group, 30.8% were malnourished and 23.1% had stunting. A greater impairment of lean body mass was found in these patients. Concentrations of triglycerides (TG), total cholesterol (CT), LDL-c, non-HDL cholesterol (NHDL-c) were significantly higher in patients and HDL-c, lower. Vitamin E/total lipids and vitamin E/TG ratios were lower in the AT group, and significant inverse correlation between these ratios and NHDL-c, CT/HDL-c, and LDL-c/HDL-c, log TG/HDL-c was observed in the AT group. Alanine aminotransferase correlated directly and significantly with NHDL-c, CT/HDL-c and LDL-c/HDL-c, in patients.

CONCLUSION:

The alterations of lipid metabolism biomarkers suggestive of atherosclerotic risk of male AT patients coupled with lower vitamin E/total lipids ratio and low lean body mass may complicate the clinical course of the disease and emphasizes the importance of multidisciplinary care, routine monitoring of cardiovascular biomarkers and appropriate nutritional guidance.

2015 S. Karger AG, Basel.

OBJECTIVE:

Ataxia telangiectasia (A-T) is a rare genetic multiorgan disease. Although gastrointestinal involvement is known, hepatic involvement in A-T has not been investigated. We aimed to study the hepatic involvement in a large cohort of patients with A-T.

METHODS:

A retrospective review of patients, studied from January 1986 to January 2015 at a National A-T Center. Clinical data including demographic, genetic, laboratory, nutritional, radiographic, and histological data were retrieved.

RESULTS:

Fifty-three patients, 27 (49%) boys, age 14.6 ± 5.2 years (range 5.9-26.1 years), were included. Twenty-three patients (43.4%), age 9.9 ± 5.1 years, had consistently abnormal liver enzymes. The mean enzyme levels were alanine aminotransferase 76.8 ± 73.8 IU/L, aspartate aminotransferase 70 ± 50 IU/L, alkaline phosphatase 331 ± 134 IU/L, and gamma glutamyl transferase 114.7 ± 8 IU/L. Evaluation of other etiology of liver disease was negative. Ultrasonography revealed fatty liver in 9 of them (39%). Liver biopsy was performed in 2 patients, revealing mild-to-moderate steatosis in both, and fibrosis in 1 patient. Progression to advanced liver disease occurred in 2 of 23 (9%) patients within 2 to 5 years. Dyslipidemia was significantly associated with abnormal liver enzymes: 3 of 30 (10%) patients without abnormal liver enzymes versus 10 of 23 (45.5%) patients with abnormal liver enzymes, respectively (P < 0.05, Fisher exact test). No correlation was found between hepatic involvement and HbA1C, sex, presence of malignancy, or type of mutation.

CONCLUSIONS:

Abnormal liver enzymes and fatty liver are common in patients with A-T and may progress to advanced liver disease at a young age. These findings are novel and implicate that patients with A-T with abnormal liverenzymes should be evaluated for the presence of liver disease.

BACKGROUND:

Ataxia-telangiectasia (A-T) is a devastating human autosomal recessive disorder that causes progressive cerebellar ataxia, immunodeficiency, premature aging, chromosomal instability and increased cancer risk. Affected patients show growth failure, poor weight gain, low body mass index (BMI), myopenia and increased fatigue during adolescence. The prevalence of alterations in body composition, muscle strength and hormonal status has not been well described in classical A-T patients. Additionally, no current guidelines are available for the assessment and management of these changes.

METHODS:

We analyzed body composition, manual muscle strength and hormonal status in 25 A-T patients and 26 age-matched, healthy controls. Bioelectrical impedance analysis (BIA) was performed to evaluate the bodycomposition, fat-free mass (FFM), body cell mass (BCM), extracellular matrix (ECM), phase angle (PhA), fat mass (FM) and ECM to BCM ratio. Manual muscle strength was measured using a hydraulic hand dynamometer.

RESULTS:

The BMI, FFM and PhA were significantly lower in A-T patients than in controls (BMI 16.56 ± 3.52 kg/m(2) vs. 19.86 ± 3.54 kg/m(2); Z-Score: -1.24 ± 1.29 vs. 0.05 ± 0.92, p <0.001; FFM 25.4 ± 10.03 kg vs. 41.77 ± 18.25 kg, p < 0.001; PhA: 4.6 ± 0.58° vs. 6.15 ± 0.88°, p < 0.001). Manual muscle strength was significantly impaired in A-T patientscompared with controls (10.65 ± 10.97 kg vs. 26.8 ± 30.39 kg, p < 0.0001). In addition, cortisol and dehydroepiandrosterone sulfate (DHEAS) levels were significantly lower in A-T patients than in controls.

CONCLUSION:

Altered body composition, characterized by depleted BMI, PhA and BCM; by the need to sit in a wheelchair; by altered hormone levels; and by poor muscle strength, is a major factor underlying disease progression and increased fatigue in A-T patients.

TRIAL REGISTRATION:

ClinicalTrials.gov NCT02345200.

AIM:

Ataxia-telangiectasia (A-T) is a rare genomic syndrome resulting in severe disability. Chronic childhood disorders can profoundly influence growth and development. Nutrition-related issues in A-T are not well described, and there are no nutritional guidelines. This study investigated the nutrition-related characteristics and behaviours of Australian A-T patients attending a national clinic.

METHODS:

A cross-sectional analysis of 13 A-T patients (nine females; aged: 4-23 years): nutritional status was assessed by anthropometric and body cell mass (BCM) calculations. Parents reported their child's diet history and physical and behavioural factors that affect nutrition including fatigue and need for assistance.

RESULTS:

Ten (77%) had short stature (height for age z scores <-1), and seven (54%) were underweight for height (weight/height z scores <-1). Significant malnutrition (BCM z scores <-2) was detected in nine (69%) including the one adult who was severely malnourished. Malnutrition increased significantly with age (BCM for height z scores and age, r = -0.937, P < 0.001). Eight (62%) patients ate poorly compared with estimated energy requirement for weight. Poor diet quality was characterised by high fat and sugar choices. Parents reported significant nutritional barriers as chronic tiredness and the need for care giver assistance with meals.

CONCLUSIONS:

This study confirms profound malnutrition in Australian A-T patients. Poor intakes and diet quality suggest the need for early nutrition intervention. Ongoing support for families and early discussions on tube feeding are required to address changing needs in childhood and likely nutritional decline into adulthood. A prospective study is required to assess feasibility and effectiveness of nutrition interventions in young people with A-T.

© 2015 The Authors. Journal of Paediatrics and Child Health © 2015 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

AIM:

To assess the relationship between genotype and neurological progression in ataxia-telangiectasia (A-T).

METHODS:

Clinical and laboratory data were extracted retrospectively from the records of patients attending the UK National Ataxia-Telangiectasia Clinic. Neurological assessments were performed using the A-T Index (Crawford Score) and the A-T Neurological Examination Scale Toolkit (A-T NEST). Variables influencing phenotype were identified by using an information-theoretic approach starting from a maximal model to generate estimates of coefficients for each variable. Per-individual progression was assessed for patients with three or more clinic attendances.

RESULTS:

The genotype could be determined for 125/135 patients. Crawford and A-T NEST scores were well correlated. For both scoring systems the estimated coefficients were significantly positive for Age x kinase activity but not Age x protein expression. Unlike the per-genotype analysis, the individual progression of neurological scores in the 34 patients that attended on three or more occasions was not smooth and linear (and in some cases improved over time).

INTERPRETATION:

Residual kinase activity confers a milder phenotype but there is no difference between kinase-dead and protein-null genotypes. The non-linear progression of individual patients' neurological scores may reflect biological complexity, day-to-day variability, limitations of the assessment methods or a combination of all three.

© 2016 Mac Keith Press.

Ataxia-telangiectasia (AT) is an autosomal recessive neurodegenerative disorder with immunodeficiency and an increased risk of developing cancer, caused by mutations in the ataxia-telangiectasia mutated (ATM) gene. Logically, blood relatives may also carry a pathogenic ATM mutation. Female carriers of such a mutation have an increased risk of breast cancer. Other health risks for carriers are suspected but have never been studied systematically. Consequently, evidence-based guidelines for carriers are not available yet. We systematically analyzed all literature and found that ATM mutation carriers have a reduced life expectancy because of mortality from cancer and ischemic heart diseases (RR 1.7, 95% CI 1.2-2.4) and an increased risk of developing cancer (RR 1.5, 95% CI 0.9-2.4), in particular breast cancer (RRwomen 3.0, 95% CI 2.1-4.5), and cancers of the digestive tract. Associations between ATM heterozygosity and other health risks have been suggested, but clear evidence is lacking. Based on these results, we propose that all female carriers of 40-50 years of age and female ATM c.7271T>G mutation carriers from 25 years of age onwards be offered intensified surveillance programs for breast cancer. Furthermore, all carriers should be made aware of lifestyle factors that contribute to the development of cardiovascular diseases and diabetes.

Ataxia-telangiectasia (A-T), or Louis-Bar syndrome, is a rare neurodegenerative disorder associated with immunodeficiency. For families with at least one affected child, timely A-T genotyping during any subsequent pregnancy allows the parents to make an informed decision about whether to continue to term when the fetus is affected. Mutations in the ATM gene, which is 150 kb long, give rise to A-T; more than 600 pathogenic variants in ATM have been characterized since 1990 and new mutations continue to be discovered annually. Therefore, limiting genetic screening to previously known SNPs by PCR or hybridization with microarrays may not identify the specific pathogenic genotype in ATM for a given A-T family. However, recent developments in next-generation sequencing technology offer prompt high-throughput full-length sequencing of genomic fragments of interest. This allows the identification of the whole spectrum of mutations in a gene, including any novel ones. We report two A-T families with affected children and current pregnancies. Both families are consanguineous and originate from Caucasian regions of Russia and Azerbaijan. Before our study, no ATM mutations had been identified in the older children of these families. We used ion semiconductor sequencing and an Ion AmpliSeq™ Inherited Disease Panel to perform complete ATM gene sequencing in a single member of each family. Then we compared the experimentally determined genotype with the affected/normal phenotype distribution in the whole family to provide unambiguous evidence of pathogenic mutations responsible for A-T. A single novel SNP was allocated to each family. In the first case, we found a mononucleotide deletion, and in the second, a mononucleotide insertion. Both mutations lead to truncation of the ATM protein product. Identification of the pathogenic mutation in each family was performed in a timely fashion, allowing the fetuses to be tested and diagnosed. The parents chose to continue with both pregnancies as both fetuses had a healthy genotype and thus were not at risk of A-T.

Ataxia-telangiectasia (A-T) is a rare genetic disorder caused by loss of function of the ataxia-telangiectasia-mutated kinase and is characterized by a predisposition to cancer, pulmonary disease, immune deficiency and progressive degeneration of the cerebellum. As animal models do not faithfully recapitulate the neurological aspects, it remains unclear whether cerebellar degeneration is a neurodevelopmental or neurodegenerative phenotype. To address the necessity for a human model, we first assessed a previously published protocol for the ability to generate cerebellar neuronal cells, finding it gave rise to a population of precursors highly enriched for markers of the early hindbrain such as EN1 and GBX2, and later more mature cerebellar markers including PTF1α, MATH1, HOXB4, ZIC3, PAX6, and TUJ1. RNA sequencing was used to classify differentiated cerebellar neurons generated from integration-free A-T and control induced pluripotent stem cells. Comparison of RNA sequencing data with datasets from the Allen Brain Atlas reveals in vitro-derived cerebellar neurons are transcriptionally similar to discrete regions of the human cerebellum, and most closely resemble the cerebellum at 22 weeks post-conception. We show that patient-derived cerebellar neurons exhibit disrupted gene regulatory networks associated with synaptic vesicle dynamics and oxidative stress, offering the first molecular insights into early cerebellar pathogenesis of ataxia-telangiectasia.

Ataxia-telangiectasia (A-T) a multisystem disorder primarily characterized by cerebellar degeneration, telangiectasia, immunodeficiency, cancer susceptibility and radiation sensitivity. Identification of the gene defective in this syndrome, ataxia-telangiectasia mutated gene (ATM), and further characterization of the disorder together with a greater insight into the function of the ATM protein have expanded our knowledge about the molecular pathogenesis of this disease. Area covered: In this review, we have attempted to summarize the different roles of ATM signaling that have provided new insights into the diverse clinical phenotypes exhibited by A-T patients. Expert commentary: ATM, in addition to DNA repair response, is involved in many cytoplasmic roles that explain diverse phenotypes of A-T patients. It seems accumulation of DNA damage, persistent DNA damage response signaling, and chronic oxidative stress are the main players in the pathogenesis of this disease.

AIM:

Visual impairment is present in almost all patients with ataxia telangiectasia (AT) and, due to their early onset, constitute an important disabling aspect of the syndrome: the quality of vision is limited by dyspraxia and oculomotor abnormal movements. The purpose of this observational study was to describe visual disorders, notably oculomotor impairment, in a sample of children with AT.

METHODS:

Fifteen AT patients (mean age 12 years and 4 months) underwent a neurovisual evaluation, particularly focused on oculomotor functions (fixation, smooth pursuit, saccades, and abnormal ocular movements). We compared the visual profile obtained with that described using the International Cooperative Ataxia Rating Scale (ICARS) subscale of oculomotor dysfunction.

RESULTS:

Refractive errors were seen in eight patients and strabismus in three. Major oculomotor findings were fixation abnormalities (6/15), saccadic impairment (15/15), and abnormal smooth pursuit (14/15). Abnormal ocular movements were seen in 13/15 (saccadic intrusion in 8 and nystagmus in 5). Using ICARS scale, 13/15 children presented gaze-evoked nystagmus, 4/15 a clearly saccadic pursuit, and 11/15 dysmetria of saccades.

DISCUSSION:

We propose a clinical neurovisual evaluation, which could be integrated with ICARS scores in the study of oculomotor involvement in AT pediatric patients. We strongly recommend the empowerment of visual functions to slow down progressive global disability of these patients.

Georg Thieme Verlag KG Stuttgart · New York.

Recent studies have linked constitutive telomere length (TL) to aging-related diseases including cancer at different sites. ATM participates in the signaling of telomere erosion, and inherited mutations in ATM have been associated with increased risk of cancer, particularly breast cancer. The goal of this study was to investigate whether carriage of an ATM mutation and TL interplay to modify cancer risk in ataxia-telangiectasia (A-T) families.The study population consisted of 284 heterozygous ATM mutation carriers (HetAT) and 174 non-carriers (non-HetAT) from 103 A-T families. Forty-eight HetAT and 14 non-HetAT individuals had cancer, among them 25 HetAT and 6 non-HetAT were diagnosed after blood sample collection. We measured mean TL using a quantitative PCR assay and genotyped seven single-nucleotide polymorphisms (SNPs) recurrently associated with TL in large population-based studies.HetAT individuals were at increased risk of cancer (OR = 2.3, 95%CI = 1.2-4.4, P = 0.01), and particularly of breast cancer for women (OR = 2.9, 95%CI = 1.2-7.1, P = 0.02), in comparison to their non-HetAT relatives. HetAT individuals had longer telomeres than non-HetAT individuals (P = 0.0008) but TL was not associated with cancer risk, and no significant interaction was observed between ATM mutation status and TL. Furthermore, rs9257445 (ZNF311) was associated with TL in HetAT subjects and rs6060627 (BCL2L1) modified cancer risk in HetAT and non-HetAT women.Our findings suggest that carriage of an ATM mutation impacts on the age-related TL shortening and that TL per se is not related to cancer risk in ATM carriers. TL measurement alone is not a good marker for predicting cancer risk in A-T families.

INTRODUCTION:

Ataxia telangiectasia (A-T) is a devastating autosomal recessive disorder with chromosomal instability and growth failure. Low levels of growth hormone (GH) and growth factors may be related to advanced neurological deterioration, wasting syndrome and more pronounced immunodeficiency.

OBJECTIVE:

The objective of this study is to study safety and effectiveness of GH therapy in patients with A-T and evaluate the effect of GH on ataxia and lymphocyte subsets.

METHODS:

Three patients with classical A-T were treated with GH (0.3 mg/kg/d) for 1 year. Growth rate, ataxia score and lymphocyte subsets were monitored.

RESULTS:

GH treatment was well tolerated. All patients showed a significant increase of height SDS of +1.3 (mean height SDS -1.994), a mean increase of 8 (6-11) cm/12 months. Lymphocytes subsets and ataxia were not altered before and after GH treatment.

CONCLUSIONS:

Treatment with GH is feasible and effective in A-T patients with severe growth arrest, but no effect on ataxia and lymphocytes could be recorded.

Ataxia telangiectasia mutated (ATM) gene mutations may confer increased sensitivity to ionizing radiation and increased risk of late toxicity for cancer patients. We present the case of a 55-year-old female treated with adjuvant breast and regional nodal radiation following lumpectomy and axillary lymph node dissection for stage II invasive ductal carcinoma of the breast. She developed severe telangiectasia, fibrosis, induration, chest wall pain (with evidence of rib fractures on imaging), and painful limitation in her range of motion at the shoulder. She was subsequently found to have a likely pathogenic germline ATM gene mutation. At relapse, she elected to pursue systemic therapy alone for intracranial metastases.

INTRODUCTION:

The ataxia telangiectasia syndrome (AT) is a genetic disease with an autosomal recessive inheritance pattern, with multisystem involvement and a broad clinical spectrum. It is caused by the mutation of the ATM gene, causing reduction or absence of the ATM proteinkinase, altering processes in the cell cycle, DNA repair and apoptosis. The objective of this article is to report the case of a patient with ataxia telangiectasia syndrome, caused by a mutation not previously reported in the literature.

CASE REPORT:

A 14 year-old patient native to Colombia, with classic clinical and phenotypical manifestations of AT syndrome, which started at 6 years of age with pondostatural alteration, recurrent respiratory infections, oculocutaneus telangiectasias and progressive neurological disorder that included: regression in her psychomotor development, ataxia and oculomotor apraxia. ATM gene sequencing is performed evidencing a homozygous mutation not reported in literature.

DISCUSSION:

In Latin America are sparse the number of reports of patients with ataxia telangiectasia and only few of these describe their molecular findings. Molecular studies allow the diagnosis and a better orientation in the management and prognosis of patients with neurodegenerative diseases. The report of undescribed molecular variants is of great importance to establish the etiology of such diseases in diverse population groups, such as the countries of Latin America.

BACKGROUND:

Ataxia telangiectasia (A-T) is a neurodegenerative disease that leads to mitochondrial dysfunction and oxidative stress. Insulin resistance (IR), type 2 diabetes and the risk for development of cardiovascular disease was recently associated as an extended phenotype of the disease. We aimed to assess IR; liver involvement; carotid intima-media thickness (cIMT) and metabolic alterations associated to cardiovascular risk in A-T patients, and relate them with age.

RESULTS:

Glucose metabolism alterations were found in 54.6% of the patients. Hepatic steatosis was diagnosed in 11/17 (64.7%) A-T patients. AST/ALT ratio > 1 was observed in 10/17 (58.8%). A strong positive correlation was observed between insulin sum concentrations with ALT (r = 0.782, p < 0.004) and age (r = 0.818, p = 0.002). Dyslipidemia was observed in 55.5% of the patients. The apolipoprotein (Apo-B)/ApoA-I ratio (r = 0.619; p < 0.01), LDL/HDL-c (r = 0.490; p < 0.05) and the Apo-B levels (r = 0.545; p < 0.05) were positively correlated to cIMT.

CONCLUSIONS:

Metabolic disorders implicated in cardiovascular and liver diseases are frequently observed in adolescent A-T patients and those tend to get worse as they become older. Therefore, nutritional intervention and the use of drugs may be necessary.

Ataxia telangiectasia (AT) is a progressive multisystem autosomal recessive disorder caused by mutations in the AT-mutated (ATM) gene. Early onset AT in children is characterized by cerebellar degeneration, leading to motor impairment. Lung disease and cancer are the two most common causes of death in AT patients. Accelerated thymic involution may contribute to the cancer, and recurrent and/or chronic respiratory infections may be a contributing factor to lung disease in AT. AT patients have fertility issues, are highly sensitive to ionizing radiation and they present oculocutaneous telangiectasia. Current treatments only slightly ameliorate disease symptoms; therapy that alters or reverses the course of the disease has not yet been discovered. Previously, we have shown that ATM^-/- pigs, a novel model of AT, present with a loss of Purkinje cells, altered cerebellar cytoarchitecture and motor coordination deficits. ATM^-/- porcine model not only recapitulates the neurological phenotype, but also other multifaceted clinical features of the human disease. Our current study shows that ATM^-/- female pigs are infertile, with anatomical and functional signs of an immature reproductive system. Both male and female ATM^-/- pigs show abnormal thymus structure with decreased cell cycle and apoptosis markers in the gland. Moreover, ATM^-/- pigs have an altered immune system with decreased CD8⁺ and increased natural killer and CD4⁺CD8⁺ double-positive cells. Nevertheless, ATM^-/- pigs manifest a deficient IgG response after a viral infection. Based on the neurological and peripheral phenotypes, the ATM^-/- pig is a novel genetic model that may be used for therapeutic assessments and to identify pathomechanisms of this disease.

Ataxia telangiectasia (AT) is a rare incurable genetic disease caused by biallelic mutations in the Ataxia telangiectasia-mutated gene. Intra-erythrocyte infusion of dexamethasone improves clinical outcomes in AT patients; however, the molecular mechanisms that lead to this improvement remain unknown. Hence, to gain a better understanding of these mechanisms, we assessed the effects of glucocorticoid administration on gene expression in the blood of AT patients. Whole blood was obtained from nine children enrolled in a phase two clinical trial, who were being treated with dexamethasone (AT Dexa), from six untreated AT patients (AT) and from six healthy volunteers (WT). CodeLink Whole Genome Bioarrays were used to assess transcript expression. The reliability of the differentially expressed genes (DEGs) was verified by qRT-PCR analysis. The enriched Gene Ontology (GO) terms and the pathways of the Kyoto Encyclopedia of Genes and Genomes (KEGG) of DEGs obtained by group comparisons were achieved using the Database for Annotation, Visualization and Integrated Discovery (DAVID). Functional network analyses were computed by Reactome FI. The likely involved transcription factors were revealed by iRegulon. Among the identified DEGs influenced by the pathology and restored by dexamethasone, we detected 522 upregulated probes coding for known proteins, while 22 probes were downregulated, as they were in healthy subjects. These results provide useful information and represent a first step towards gaining a better understanding of the underlying mechanisms of the effects of dexamethasone on AT patients.

Ataxia telangiectasia (A-T) is a neurodegenerative autosomal recessive disorder with the main characteristics of progressive cerebellar degeneration, sensitivity to ionizing radiation, immunodeficiency, telangiectasia, premature aging, recurrent sinopulmonary infections, and increased risk of malignancy, especially of lymphoid origin. Ataxia Telangiectasia Mutated gene, ATM, as a causative gene for the A-T disorder, encodes the ATM protein, which plays an important role in the activation of cell-cycle checkpoints and initiation of DNA repair in response to DNA damage. Targeted next-generation sequencing (NGS) was performed on an Iranian 5-year-old boy presented with truncal and limb ataxia, telangiectasia of the eye, Hodgkin lymphoma, hyper pigmentation, total alopecia, hepatomegaly, and dysarthria. Sanger sequencing was used to confirm the candidate pathogenic variants. Computational docking was done using the HEX software to examine how this change affects the interactions of ATM with the upstream and downstream proteins. Three different variants were identified comprising two homozygous SNPs and one novel homozygous frameshift variant (c.80468047delTA, p.Thr2682ThrfsX5), which creates a stop codon in exon 57 leaving the protein truncated at its C-terminal portion. Therefore, the activation and phosphorylation of target proteins are lost. Moreover, the HEX software confirmed that the mutated protein lost its interaction with upstream and downstream proteins. The variant was classified as pathogenic based on the American College of Medical Genetics and Genomics guideline. This study expands the spectrum of ATM pathogenic variants in Iran and demonstrates the utility of targeted NGS in genetic diagnostics.