In the total sample, two SNPs, rs1404697 and rs848353, located on chromosome 7q31.1, were associated with ND, with p values <10−5. Further analysis of the male sample revealed four additional SNPs associated with ND with p values <10−5: rs1404697 and rs848353 on chromosome 7, rs12536963 in EXOC4 on chromosome 7, and rs4424567 in FRMD4A on chromosome 10. Two SNPs, rs1404697 and rs848353, were identified in both the total and male samples.