| We have examined the following possible linked markers in 69 relatives in this family : the c ret gene ( HSCR ) ; the human PAX 3 gene ( HuP 2 ) on chromosome 2q ( WS 1 ) and placental alkaline phosphatase ( ALPP ) on chromosome 2q ( linked to WS 1 ) ; argininosuccinate synthetase ( ASS ) on chromosome 9q , close to ABO blood groups which have shown weak linkage to WS ; and the beta 1 GABA receptor gene ( GABARB 1 ) on chromosome 4q13 11 , close to c kit , deletions of which cause piebaldism . ^^^ |