Clefting disorders
Region: ISCA-46303-LossSOX9 upstream enhancer loss
Deletion of the upstream enhancer of SOX9 have been associated with Pierre Robin syndrome, campomelic dysplasia, acampomelic dysplasia as well as 46,XY sex reversal.
This region has been curated by Clingen for the Pierre Robin syndrome phenotype and has been called HI3. Coordinates were based on the largest region found in affected individuals.
There are a number of enhancer elements within this region of which there are proposed to be four clusters: a proximal cluster between 50-375 kb, a sex-determining interval RevSex region between 517-595 kb, a distal cluster between 601 and 932 kb, and a PRS cluster between 1.03–1.26 Mb. Defining genotype phenotype has not been conclusively established within the literature in this region however there are some noted correlations.
Incomplete penetrance has been noted for the 46,XY sex reversal with approx 75% of individuals with deletions in this region demonstrating a DSD phenotype ranging from ambiguous genitalia to typical female external genitalia. Note that loss of SOX9 function does not cause sex reversal in individuals with a 46,XX karyotype. See additional entry for gain of this region.
Sources: ClinGenCreated: 6 Feb 2026, 2:14 p.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications
Region: isca-46303-loss has been classified as Green List (High Evidence).
Phenotypes for Region: ISCA-46303-Loss were changed from to Pierre Robin syndrome MIM#261800 Tag regulatory region was added to Region: ISCA-46303-Loss.
Region: isca-46303-loss has been classified as Green List (High Evidence).
Region: ISCA-46303-Loss was added Region: ISCA-46303-Loss was added to Clefting disorders. Sources: ClinGen Mode of inheritance for Region: ISCA-46303-Loss was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for Region: ISCA-46303-Loss were set to PMID: 24934569, 26663529, 19234473, 26152199, 30552336