Nine year old boy with chromosome 1q23.3-q25.1 deletion.

Interstitial deletions of the long arm of chromosome 1 are rare, and recent reports of individuals with molecularly characterized deletions have resulted in advances in genotype-phenotype correlation. The recognizable phenotype associated with 1q23.3-q25.1 includes pre- and post-natal growth retardation, microcephaly, intellectual disability, delayed language acquisition, small hands and feet with brachydactyly and single palmar crease, and distinctive facial features including short bulbous nose, micrognathia, and ear malformations. We report a patient with an 11.35 Mb deletion from 1q23.3-q25.1 who has these features in addition to a rarely reported complication-profound sensorineural hearing loss. He has both pre- and post-natal growth deficiency and growth hormone deficiency that was diagnosed at age 2 years. However, unlike other individuals with this deletion and growth hormone deficiency, this boy has responded to treatment with human growth hormone. © 2016 Wiley Periodicals, Inc.