Clinical Association of Ataxia Telangiectasia-Like Disorder 1 with an Uncertain Significance Variant in the MRE11 Gene: A Case Report

Objective: Ataxia telangiectasia-like disorder (ATLD) is a rare autosomal recessive disorder caused by mutations in the MRE11 gene. The diagnosis of patients with Ataxia telangiectasia-like disorder and Ataxia telangiectasia may be challenging due to similar clinical manifestations. In the present study, we describe a patient with a homozygous variant of uncertain significance (VUS) in the MRE11 gene that was correlated clinically with ATLD. Methods: We performed a brain MRI scan to find the cause of the patient's ataxia. After ventriculoperitoneal shunting due to obstructive hydrocephalus, there was no clinical change; so, we carried out whole exome sequencing. Additionally, Variants were classified using several databases and predicted according to the ACMG 2015 guidelines. Results: A 2-year-6-month-old boy with ataxia, tonic seizure, and speech delay was found during studies. The WES and in silico analysis identified a homozygous variant of uncertain significance (VUS) in the MRE11 NM_005591.4 (MRE 11): c.173 G>T (p. GIv58Val).Conclusion: This case report highlights that genetic testing can be useful for the precise diagnosis when clinical manifestations are not associated with MRI results. Furthermore, we could categorize a variant in the MRE11 gene from VUS to likely pathogenic based on clinical features.