Silver-Russell syndrome-like features in a child with recombinant chromosome 11 derived from maternal pericentric inversion.

Silver-Russell syndrome (SRS) is a well-known syndrome but with heterogeneous etiologies. We present the case of a child with severe SRS-like features resulting from a complex rearrangement of chromosome 11 inherited from his mother. We studied the index case with karyotyping, MS-MLPA and molecular karyotyping. The mother was studied with karyotyping and subtelomeric FISH. We found a child with marked developmental delay and fatal outcome due to failure to thrive, carrying an 11p15 duplication and an 11q25 deletion of maternal origin. We discovered that the mother was a carrier of a pericentric inversion of chromosome 11, with a history of recurrence in other family members who had severe growth retardation and early death. To our knowledge, no similar SRS-like cases have been described in the literature. This report supports the importance of identification the causative genetic mechanism in SRS-like individuals with duplication in 11p15 region due to high risk of recurrence and to provide an appropriate genetic counseling to the family.

Somatic Mosaicism for Paternal Uniparental Disomy of 11p15.5 Region in Adrenal and Liver Tissues in a Newborn with Atypical Beckwith-Wiedemann Syndrome.

Beckwith-Wiedemann syndrome (BWS) is characterized by overgrowth and increased risk of embryonic tumors. It results from alterations in genes controlled by imprinting centers H19DMR (Imprinting Center [IC] 1) and KvDMR (IC2). Strategies for diagnostic confirmation include methylation analysis and CDKN1C sequencing. We present a newborn with placentomegaly, hyperinsulinism and adrenal cytomegaly, but no typical external features of BWS. The patient had normal genetic studies in blood. However, adrenal and liver tissues showed hypermethylation of IC1 and hypomethylation of IC2. Microsatellite analysis confirmed mosaic paternal uniparental disomy. This study demonstrates the importance of analyzing additional tissues to reduce underdiagnosis of somatic mosaicism in BWS.