Our CHD7 detection rate was consistent with that reported in previous four studies, which explored CHD7 variants in CHH patients, with detection rates of 16% (18/116) (Xu et al., 2018), 16% (8/50) (Gonçalves et al., 2019), 10.2% (18/177) (Li et al., 2020), and 6% (6/101)9. This evidence concerns the gene CHD7 and cartilage-hair hypoplasia.