The First Reported Case of Meckel-Gruber Syndrome Associated With Abnormal Karyotype Mosaic Trisomy 17.

Meckel-Gruber syndrome (MKS) is a rare lethal autosomal recessive disorder with typical anomalies including encephalocele, multicystic renal dysplasia, congenital liver fibrosis, and polydactyly. MKS is caused by mutations of genes localized on different chromosomes. Karyotypes of published Meckel-Gruber syndrome cases are without any aberrations. We present a male fetus with meningoencephalocele, multicystic renal dysplasia, congenital liver fibrosis, and other anomalies. Standard cytogenetic examination of cultured fetal skin and muscle fibroblasts showed mosaic trisomy 17. Homozygous deletion in CC2D2A gene was found by Sanger sequencing. This is to our knowledge the first case of genetically confirmed Meckel-Gruber syndrome with incidental cofinding of mosaic trisomy 17. Abnormal karyotype does not exclude diagnosis of MKS with risk of recurrence 25% in next pregnancy. In the case of anomalies typical for Meckel-Gruber syndrome, genetic analysis is indicated.