Different phenotypes of moyamoya disease in a Chinese familial case involving heterozygous c.14429G>a variant in RNF213.

PURPOSE: Moyamoya disease (MMD) is an uncommon chronic and occlusive cerebrovascular disorder involving the development of abnormal collateral vessels. This report aimed to describe a Chinese familial case with a rare variant in the RNF213 gene.

METHODS

The present report presents a rare familial case of MMD involving a heterozygous c.14429G>A variant in RNF213 and exhibiting different phenotypes.

RESULTS

A 3-year-old Chinese boy and his 10-year-old sister diagnosed severe bilateral MMD, while their mother was diagnosed asymptomatic bilateral MMD, based on the imaging results of magnetic resonance angiography (MRA). The boy mainly showed numbness at left hand accompanied by dysphasia and dyskinesia, while his sister had complex symptoms including dysphasia, dyskinesia at both hands and fatigue of limbs. Muscle force was ranked as left (upper limb/lower limb: 4/3) and right (upper limb/lower limb: 3/4). Genetic testing indicated a heterozygous c.14429G>A variant in RNF213 in 3 patients. The 3 patients shared the same amino acid substitution of p.Arg4810Lys caused by c.14429G>A. The father of two children also underwent genetic testing for RNF213 and MRI examination but found normal in all indices.

CONCLUSIONS

Genetic testing for RNF213 is suggested for MMD screening towards family members, and c.14576G>A variant is identified as an important pathogenic mutation with family heritability.