CYP27A1 and cerebrotendinous xanthomatosis: Three novel variants including c.368_374delCCAGTAC, c.389 T > A (p.M130K) and c.571C > T (p.Q191*), and 7 previously reported pathogenic mutations (c.379C > T, c.435G > T, c.1016C > T, c.1214G > A, c.1263 + 1G > A, c.1420C > T and c.1435C > T) in CYP27A1 (ClinVar database: https://www.ncbi.nlm.Nih.gov/clinvar/) were identified in 6 CTX families.