Identification of two novel cerebrospinal fluid proteins in non specific mental retardation.

Cerebrospinal fluid (CSF) from twenty three patients with non specific mental retardation and fourteen age matched normal samples was subjected for qualitative analysis of protein profiles by two-dimensional gel electrophoresis (2-DE) and the proteins were visualised by ultra sensitive silver staining. Two proteins designated as mental retardation associated proteins (MRAP-I and MRAP-II) were identified in six male patients out of twenty three patients CSF samples. MRAP-I had an isoelectric point of 7.4 with a relative molecular weight 16.5 kDa, while MRAP-II had an iso-electric point of 7.2 with a relative molecular weight 16.8 kDa. The two proteins are presumed to be originated from brain, as they could not be traced in the serum of patients, nor due to proteolytic degradation. Despite unknown origin and identity, their presence in the CSF of a specific group of mentally retarded male patients suggest their possible clinical utility and to define protein alterations in mental retardation.