“…3 3 Among the cases listed in Table 1, all the familial cases occurred only in siblings. Autosomal recessive inheritance may be suggested, but no consanguinity was reported in those cases, except for the case described by Hunter et al24 Gene defect was implicated in the murine mutant, &dquo;iveaver,&dquo; with granule cell degeneration The wide variety of clinical manifestations among those familial cases (cases 8,9,11,12,[14][15][16]20, and 21 from Table 1)3--6,'2,m,2~,2b suggests that the gene defect for this disease may not be in a single allele, and modified defects in a gene locus may be responsible for the varied time of death and clinical severity. No notable clinical difference can be identified in sporadic cases (cases 1-7,10,13,17-19 from Table It,8-l1,25,27-29 when compared with the familial cases.…”