Molecular characterization of cytogenetic alterations associated with the Beckwith-Wiedemann syndrome (BWS) phenotype refines the localization and suggests the gene for BWS is imprinted.

To define the region of 11p15 involved in Beckwith-Wiedemann syndrome (BWS), we have carried out a molecular genetic analysis of six patients with features of BWS and constitutional cytogenetic abnormalities involving chromosome band 11p15. Molecular analysis confirmed the 11p origin of the duplicated material and defined the smallest region of overlap for such duplications, within which a gene involved in BWS must be located. This region encompasses the beta-globin gene complex (HBB) to 11pter.

Cri du chat syndrome due to meiotic recombination in a pericentric inversion 5 carrier.

A female infant presented at birth with hypotonia, growth retardation, distinctive facies, multiple congenital anomalies, and a high-pitched mewing cry characteristic of cri du chat syndrome. Chromosome studies from both peripheral blood and fibroblasts showed a 46,XX,5p- karyotype. Parental chromosome studies revealed that the mother carried an apparently balanced pericentric inversion of one chromosome no.

Cytogenetic analysis of 400 sperm from three translocation heterozygotes.

Sperm chromosome complements were studied in three men who carried reciprocal translocations. A total of 400 sperm were karyotyped after in vitro penetration of hamster eggs: 217 sperm from t(2;9) (q21;p22), 164 from t(4;6)(q28;p23) and 19 from t(7;14) (q21;q13). All possible 2:2 and 3:1 meiotic segregations were observed for t(2;9) and t(4;6); for t(7;14) only 2:2 segregations were observed.

A familial interstitial deletion of the long arm of chromosome 21.

A mother and daughter with an interstitial deletion of the chromosome segment 21q11 to 21q21.3 have similar minor dysmorphism and mild mental retardation. These two patients are compared to others in the literature with deletion of the same region of chromosome 21.

Chromosome 6q deletions: a report of two additional cases and a review of the literature.

Here we report on two additional cases of distal 6q deletions with one case showing a terminal deletion of chromosome 6 (46,XY, del(6)(pter----q26:)) and one case showing an interstitial deletion of chromosome 6 (46,XY, del(6)(pter----q23::q25----qter)). The association of retinal abnormalities in 6q deletions is supported, and the additional manifestations of skin hyperextensibility, sacral abnormality, and imperforate anus are described.