Phenotypic comparison of a novel variant (p.P164R) and A founder mutation (c.748+1G>A) in Warburg Micro syndrome

Abstract

Warburg Micro syndrome is a rare autosomal recessive disease due to pathogenic variants found most commonly in the RAB3GAP1 gene. It is commonly seen in consanguineous marriages and is characterized by optic, neurologic, endocrinologic and some non-typical findings (cardiomyopathy, peripheral neuropathy). Here, we report two male patients from healthy consanguineous and non- consanguineous carrier parents, with homozygous variants of the RAB3GAP1 gene, presenting with bilateral congenital cataracts, hypogonadism, hypotonia and developmental delay. The first case had a novel variant and had colpocephaly as shown in his MRI brain, which has not been previously reported in the medical literature. The second case was thought to have a founder mutation for Turkey. In conclusion, there was no phenotypical difference between the novel and founder mutations. In Turkish patients suspected to have Warburg Micro syndrome, we recommend molecular testing for the detection of a founder mutation.