Background: Mitochondrial alanyl-tRNA synthetase 2 gene (AARS2) related disease is a rare genetic disorder affecting mitochondrial metabolism, leading to severe cardiac disease in infants or progressive leukodystrophy in young adults. The disease is considered ultra-rare with only 39 cases of AARS2-leukodystrophy previously reported.
Case presentation: We present the case of a young man of consanguineous heritage suffering from cognitive decline and progressive spasticity as well as weakness of the proximal musculature. Utilizing MRI and whole genome sequencing, the patient was diagnosed with a homozygous AARS2 missense variant (NM_020745.3:c.650C > T; p.(Pro217Leu)) and a homozygous CAPN3 variant (NM_000070.2: c.1469G > A; p.(Arg490Gln)), both variants have previously been identified in patients suffering from AARS2 related leukodystrophy and limb-girdle muscular dystrophy, respectively.
Conclusions: This case report presents a case of homozygous AARS2 leukodystrophy and serves to highlight the importance of whole genome sequencing in diagnosing rare neurological diseases as well as to add to the awareness of adult onset leukodystrophies.
Keywords: AARS2; AARS2, Mitochondrial alanyl-tRNA synthetase 2 gene; AARS2-L, Mitochondrial alanyl-tRNA synthetase 2 gene leukodystrophy; ADLs, activities of daily living; ALSP, Adult-Onset Leukoencephalopathy With Axonal Spheroids and Pigmented Glia; Adult onset leukodystrophies; CSF, Cerebrospinal fluid; CSF1R, Colony stimulating factor-1 receptor; Case report; DARS2, Deficiency of aspartyl-tRNA; EARS2, Deficiency of glutamate-tRNA synthetase; HDLS, Hereditary Diffuse Leukodystrophy with axonal Spheroids; IEM, Inborn errors of metabolism; Inborn errors of metabolism; LGMD R1, Limb-girdle muscular dystrophy R1 calpain3-related; Limb-girdle muscular dystrophy; MMSE, Mini-Mental State Examination; Mt-aaRS, Mitochondrial aminoacyl-tRNA synthetase; Whole genome sequencing; mtDNA, Mitochondrial DNA.
© 2021 The Authors. Published by Elsevier Inc.