Second‐trimester prenasal and prefrontal skin thickening—Association with MECP2 triplication syndrome

MECP2 triplication syndrome is a rare and usually lethal genetic disorder characterized by progressive neurologic and cognitive regression. None of the four reported cases describe prenatal sonographic features of affected offspring. We report a second‐trimester fetus with marked prefrontal and prenasal skin thickening, retrognathia, and later, third‐trimester mild cerebral ventriculomegaly. Amniocyte karyotype was normal male, but newborn whole‐genome oligonucleotide microarray showed duplication and triplication of chromosome Xq28 containing the MECP2 gene. Comparative genomic hybridization may be diagnostic in fetuses with prefrontal and prenasal skin thickening, additional sonographic findings, and normal karyotype. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 41 :434–437, 2013