48,XYYY syndrome http://purl.bioontology.org/ontology/SNOMEDCT/733625003 A rare Y chromosome number anomaly that affects only males. The disease has characteristics of mild-moderate developmental delay (especially speech), normal to mild intellectual disability, large, irregular teeth with poor enamel, tall stature and acne. Radioulnar stenosis and clinodactyly have also been associated. Boys generally present normal genitalia, while hypogonadism and infertility is frequently reported in adult males. XYYY syndrome chromosomal gain syndrome 48,XYYY allosomal chromosomal syndrome