GENETIC ENCYCLOPEDIA
ABOUT US    

   

STARD7, (ATTTC)n REPEAT EXPANSION AND Epilepsy, familial adult myoclonic 2

Significance: Pathogenic
ClinVar: RCV000855779

Variant: STARD7, (ATTTC)n REPEAT EXPANSION

Type: Variant
Allele: STARD7, (ATTTC)n REPEAT EXPANSION 682371
Gene:
Type: Variation
References: OMIM: 616712.0001

Condition

Disease: Epilepsy, familial adult myoclonic 2

Citation

    In 158 affected individuals from 22 unrelated families with familial adult myoclonic epilepsy-2 (FAME2; 607876), Corbett et al. (2019) identified a heterozygous 5-bp repeat expansion (ATTTC)n in intron 1 of the STARD7 gene. Affected individuals had variable expansion of an endogenous (ATTTT)n repeat in addition to the insertion of an abnormal (ATTTC)n repeat. The expanded repeat was initially identified using repeat expansion detection techniques to evaluate whole-genome sequencing data from 3 previously reported large FAME families who showed linkage to chromosome 2q. Using specific repeat-primed PCR (RP-PCR), the authors then identified an expanded (ATTTC)n repeat in affected individuals from 19 additional families. The (ATTTC)n repeat expansion was not found in about 100 control DNA samples. Analysis of 4 fibroblast cell lines from family 1 showed no difference in STARD7 mRNA or protein expression compared to controls, and RNA-seq data from patient-derived fibroblasts from 2 families showed no significant difference in gene expression of STARD7 between affected and unaffected individuals. The authors hypothesized that the mechanism of disease may relate to RNA toxicity.
PMID:31664034