The main strengths of our study are as follows: 1 This study systematically analyzed genotype, phenotype, and their correlation in a series of CHH patients with CHD7 gene variants; 2 19 novel variants were reported to expand the genotype spectrum; 3 Variants were classified according to the ACMG guideline, and the US type variants were further classified into US1 and US2, which provide detailed evidence for future studies; 4 Our study showed a genotype-phenotype correlation tendency, namely P or LP RSVs were more likely to cause syndromic CHH. Here, CHD7 is linked to cartilage-hair hypoplasia.