Partial trisomy 18q12, due to intrachromosomal duplication, is not associated with typical 18 trisomy phenotype.
Partial 18q12 trisomy, due to intrachromosomal duplication, was found in a severely mentally retarded boy. The finding of nonspecific dysmorphism in this patient demonstrates that trisomy of band 18q12 is accompanied by neither a full nor an incomplete 18 trisomy phenotype, indicating that this phenotype may be due solely to trisomy of the 18q11 band.
D000015:Abnormalities, Multiple / Q000235:genetics; D002648:Child; D002902:Chromosomes, Human, 16-18; D002906:Chromosomes, Human, 6-12 and X; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D010641:Phenotype; D014314:Trisomy