ASSIGNMENT OF THE HUMAN 8.5-H GENE TO CHROMOSOME-5, REGION-5Q35

The human 8.5 H probe was isolated from a human cerebellum cDNA librar y with a probe corresponding to the coding region of the murine 8.5 M cDNA. This cDNA isolated from a murine cDNA library constructed from n ewborn cerebral hemispheres was selected because of its strong express ion in embryonic neurons. Consequently the corresponding human gene co uld be a candidate for hereditary neurodegenerative diseases. The huma n 8.5 H gene was assigned by somatic hybrid analysis to chromosome 5; this chromosome contains the gene(s) for spinal muscular atrophy (SMA) , a group of heritable degenerative diseases that selectively affect t he anterior horn motor neuron of the spinal cord. The localization by in situ hybridation of 8.5 H on 5q35 excluded the possibility that thi s gene is identical to SMA. The SMB gene(s) was (were) known, from lin kage analysis, to be in a region (5q11.2-q13.3) very distant from 5q35 .