Arina Puzriakova changed review comment from: The rating of this region has been updated to Green and the mode of inheritance set to 'X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)' following NHS Genomic Medicine Service approval. Evidence: multiple unrelated cases curated in ClinGen plus several others - sufficient evidence for this region. Phenotype: syndromic intellectual disability (congenital anomalies, behavioural problems and facial dysmorphism), seizures in about 30%. Modulated phenotype in females is reported.; to: The rating of this region has been updated to Green and the mode of inheritance set to 'X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)' following NHS Genomic Medicine Service approval. Evidence: two cases (PMID: 30158690; 33758131) with intragenic STAG2 deletions but listed as sufficient evidence in ClinGen. Region encompasses STAG2 and some of XIAP. Phenotype: holoprosencephaly and/or developmental delay/ID based on LOF of STAG2 gene. Affected females are reported.