Linkage studies in peripheral neurofibromatosis.

Peripheral neurofibromatosis (NF) is one of the most common major genetic disorders in man. Its chromosomal location is unknown and questions regarding such factors as genetic heterogeneity remain unanswered. We have ascertained and sampled several large multi-generation families for linkage studies including one family of 66 subjects, 28 of whom were affected with NF. Recombinant DNA studies of several restriction fragment length polymorphisms (RFLPs) including C3, ApoC2, pBam34 (D19S6], HAUP[APRT], pE40-1 [D11521], Hp[Hp2 alpha], LDR92, and LDR111 failed to show a significant linkage (Z [lod score] greater than or equal to 3.00) in this family. In addition, the results excluded areas of the genome around the marker loci (Z greater than or equal to - 2.00) as potential sites for linkage. The maximum Z obtained with the markers was for Hp at theta (maximum recombination fraction) = 0.20 and Z = 0.399. We are now in the process of screening additional RFLPs and families for linkage to NF.