It is due to mutations in the Bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthetase 2 ( PAPSS2 ) gene which is located on the long arm of chromosome 10 (10q22-q24)
[ipfs.io]
[…] conditions: Achondroplasia Thanatophoric dysplasia types 1 and 2 Hypochondroplasia Severe achondroplasia with developmental delay and acanthosis nigricans Camptodactyly, tall
[emedicine.medscape.com]
stature, and hearing loss (CATSHL) syndrome, Crouzon syndrome with acanthosis nigricans, Hypochondroplasia, Lacrimoauriculodentodigital syndrome, Muenke syndrome, SADDAN,
[genda.com.ar]