LINKAGE OF RECESSIVE FAMILIAL AMYOTROPHIC-LATERAL-SCLEROSIS TO CHROMOSOME 2Q33-Q35

Amyotrophic lateral sclerosis (ALS) usually presents as a sporadic dis order of motor neurons. However, familial forms of ALS have been descr ibed - autosomal dominant forms (ALS1, ALS3), clinically indistinguish able from the sporadic form, and autosomal recessive forms with early onset and slower progression of symptoms (ALS2). To localize the gene for one of the autosomal recessive forms of ALS, we applied linkage an alysis to a large inbred family from Tunisia. A lod score maximum of Z (max) = 8.2 at theta=0.00 was obtained with marker D2S72 located on ch romosome 2q33-q35. The fine mapping of this region suggested that the ALS2 locus lies in the 8 cM segment flanked by D2S155 and D2S115.