The reference OMIM entry for this protein is 607151

Moyamoya disease 2; mymy2

A number sign (#) is used with this entry because evidence suggests that susceptibility to moyamoya disease-2 (MYMY2) may be conferred by variation in the RNF213 gene (613768) on chromosome 17q25.

DESCRIPTION

Moyamoya disease is a progressive cerebral angiopathy characterized by bilateral internal carotid artery stenosis and abnormal collateral vessels. The abnormal vessels resemble a 'puff of smoke' (moyamoya) on cerebral angiogram. Affected individuals can develop transient ischemic attacks and/or cerebral infarction, and rupture of the collateral vessels can cause intracranial hemorrhage (summary by Kamada et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of moyamoya disease, see MYMY1 (252350).

CLINICAL FEATURES

Liu et al. (2011) reported a Caucasian father of Czech descent and his 3 affected children with moyamoya disease. The father had a mild ischemic stroke at age 30 years, and his mother had died of ischemic stroke at age 35. The 3 children developed moyamoya disease at ages 5, 9, and 3 years, respectively. One had involuntary movements and another had signs of ischemic stroke. Diagnosis of the disorder was confirmed by brain MRI. Miyatake et al. (2012) reported 2 Japanese sibs with MYMY2 confirmed by genetic analysis. One sib was homozygous for the 14576G-A RNF213 variant (613768.0001) and the other was heterozygous for the same variant. The homozygous 21-year-old brother had a transient ischemic attack (TIA) at age 2 years and was found to have moyamoya disease. Brain imaging showed a low-density area around the right middle cerebral artery and atrophy of the right cerebral hemisphere; this was associated with left hemiparesis. Cerebral angiograms showed multiple bilateral vascular abnormalities. He had progression of the disorder, with recurrent strokes despite multiple surgeries, and slow intellectual deterioration. Residual features included headache, paresis, and visual defects. His 18-year-old sister, who was heterozygous for the mutation, had her fist transient ischemic attack at age 17 years. Brain MRI was normal, but cerebral angiograms showed unilateral changes consistent with moyamoya disease. The occlusive changes were not as severe as in her affected brother. Vascular surgery resulted in complete remission of TIAs. Family genetic analysis showed that both unaffected parents and an unaffected third sib also carried a heterozygous 14576G-A mutation. The report suggested a dosage effect for the 14576G-A variant.

OTHER FEATURES

Nishimura et al. (2003) described a 4-year-old boy with microcephalic osteodysplastic primordial dwarfism II (MOPD2; 210720) and cafe-au-lait spots who developed left hemiparesis and seizures and was found to have moyamoya disease on MRI, with infarction of the right cerebral hemisphere. FISH analysis of the neurofibromatosis locus (NF1; 162200) did not show any deletions, and the boy had no neurofibromas or Lisch nodules. Young et al. (2004) reported a second patient with MOPD2, cafe-au-lait spots, and moyamoya disease. She began having episodes of weakness and seizures at age 2.5 years; cerebral angiography revealed typical moyamoya vessels and MRI showed multiple areas of cerebral infarction. Standard karyotyping, specific sister chromatid exchange and diepoxy chromosome breakage analysis, and mitochondrial mutation testing were normal. Young et al. (2004) suggested that the list of moyamoya disease associations sho ... More on the omim web site

Subscribe to this protein entry history

Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).

Oct. 19, 2018: Protein entry updated
Automatic update: OMIM entry 607151 was added.