12q14 microdeletion syndrome and short stature with or without relative macrocephaly

Abstract

Patients with 12q14 microdeletion can present with short stature with or without relative macrocephaly. When associated with relative macrocephaly, the phenotype resembles Silver-Russell syndrome (SRS). Short stature is attributable to haploinsufficiency of HMGA2, but a patient with a deletion at the HMGA2 locus only did not have macrocephaly. Hence, the presence of a separate locus for a relative macrocephaly phenotype was suggested. Herein, we present a girl with a 12q14 microdeletion involving the HMGA2 locus who had short stature but did not have macrocephaly. Inclusion and exclusion mappings based on a quantitative review of the degree of relative macrocephaly and the extent of the deletions in previously reported patients with a 12q14 microdeletion demonstrated a presumptive interval for relative macrocephaly spanning a few megabases. These results confirm that a deletion spanning both HMGA2 and this presumptive interval locus would cause an SRS-like phenotype.