Ras Like GTPase (RLGP)

Disruption of RLGP was responsible for the patient's profound mental retardation.The patient's condition was originally misdiagnosed as cerebral palsy, and only later was it diagnosed as DMD. Because the DMD gene (dystrophin) is located at Xp21.2, which is one breakpoint of the inv(X), and because its defects are rarely associated with severe mental retardation, the other clinical features of this patient were deemed likely to be associated with the opposite breakpoint at Xq22.

The molecular-cytogenetic characterization of both breakpoints revealed 3 genetic events that probably had disastrous influence on neuromuscular and cognitive development: deletion of part of the DMD gene at Xp21.2, duplication of the proteolipid protein gene (PLP1) at Xq22.2, and disruption of a novel gene.