[show abstract][hide abstract] ABSTRACT: We report the unusual finding of velocardiofacial syndrome (VCF) in an unexplained 46,XX male. A microdeletion of 22q11.2 was confirmed by fluorescence in situ hybridization (FISH) analysis. Routine G-banded chromosome analysis revealed an XX sex chromosome constitution. FISH was performed using the SRY probe and failed to detect hybridization. The sex chromosome status of the patient was further investigated by PCR testing to screen for the presence of 24 distinct loci spanning the Y chromosome. PCR screening failed to detect any apparent Y chromosome material.
American Journal of Medical Genetics Part A 02/2003; 116A(1):77-9. · 2.30 Impact Factor
[show abstract][hide abstract] ABSTRACT: We determined the chromosomal location of the mouse gene Stk25, encoding a member of the Ste20/PAK family of serine/threonine kinases, by interspecific backcross analysis. We mapped Stk25 to the central region of mouse chromosome 1 linked to Chrng (formerly Acrg) and En1. This central region of mouse chromosome 1 shares a region of homology with the long arm of human chromosome 2, suggesting that the human homologue of Stk25 would also map to 2q. We proved this prediction of syntenic homology correct by mapping human STK25 to 2q37. Deletion of the 2q37 region has been implicated in the expression of pseudopseudohypoparathyroidism (PPHP), a disease which shares features of the Albright hereditary osteodystrophy (AHO) phenotype. To investigate a pathogenetic relationship between STK25 and PPHP, we carried out fluorescence in situ hybridization (FISH) using an STK25 gene probe and chromosomes from PPHP patients characterized as having small deletions near the distal end of 2q. PPHP patient DNA showed no hybridization to STK25 genomic DNA, indicating that STK25 is contained within the deleted chromosomal region. This finding, in conjunction with previous studies demonstrating the role of Ste20/PAK kinases in heterotrimeric G protein signaling, suggests that STK25 is a positional candidate gene for PPHP.
[show abstract][hide abstract] ABSTRACT: We report the prenatal diagnosis of an apparently balanced de novo complex chromosome rearrangement (CCR) which involved nine breakpoints on four different chromosomes. Fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY) were performed as an adjunct to G-banding for characterization of the abnormal chromosomes. The 22-week female fetus showed minor dysmorphic features including dolichocephaly, broad fingernails, tibial bowing, clubfoot, thoracolumbar scoliosis and hypoplastic toenails. Autopsy revealed gall-bladder hypoplasia and an atrial septal defect. Chromosome analysis of fetal tissue confirmed the presence of the complex rearrangement.
[show abstract][hide abstract] ABSTRACT: Of the chronic mental disabilities of childhood, autism is causally least well understood. The former view that autism was rooted in exposure to humorless and perfectionistic parenting has given way to the notion that genetic influences are dominant underlying factors. Still, identification of specific heritable factors has been slow with causes identified in only a few cases in unselected series. A broad search for genetic and environmental influences that cause or predispose to autism is the major thrust of the South Carolina Autism Project. Among the first 100 cases enrolled in the project, abnormalities of chromosome 15 have emerged as the single most common cause. The four abnormalities identified include deletions and duplications of proximal 15q. Other chromosome aberrations seen in single cases include a balanced 13;16 translocation, a pericentric inversion 12, a deletion of 20p, and a ring 7. Candidate genes involved in the 15q region affected by duplication and deletion include the ubiquitin-protein ligase (UBE3A) gene responsible for Angelman syndrome and genes for three GABA(A) receptor subunits. In all cases, the deletions or duplications occurred on the chromosome inherited from the mother.
American Journal of Medical Genetics 04/1998; 76(4):327-36.
[show abstract][hide abstract] ABSTRACT: J.M. and H.G. are two unrelated male patients with developmental delay. Cytogenetic analysis detected a duplication of 17p11.2 in both patients. The extent of the duplicated region was determined using single copy DNA probes: cen-D17S58-D17S29-D17S258-D17S71-D17S445-+ ++D17S122-tel. Four of the six markers, D17S29, D17S258, D17S71, and D17S445, were duplicated by dosage analysis. Fluorescent in situ hybridization (FISH) analysis of H.G., using cosmids for locus D17S29, confirmed the duplication in 17p11.2. Because the deletion that causes the Smith-Magnesis syndrome involves the same region of 17p11.2 as the duplication in these patients, the mechanism may be similar to that proposed for the reciprocal deletion/duplication event observed in Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and Charcot-Marie-Tooth Type 1A disease (CMT1A).
American Journal of Medical Genetics 06/1996; 63(2):373-7.