Novel homozygous mutations in the WNT10B gene underlying autosomal recessive split hand/foot malformation in three consanguineous families

Split-hand/split-foot malformation (SHFM), representing variable degree of median clefts of hands and feet, is a genetically heterogeneous group of limb malformations with seven loci mapped on different human chromosomes. However, only 3 genes (TP63, WNT10B, DLX5) for the seven loci have been identified. The study, presented here, described three consanguineous Pakistani families segregating SHFM in autosomal recessive manner. Linkage in the families was searched by genotyping microsatellite markers and mutation screening of candidate gene was performed by Sanger DNA sequencing. Clinical features of affected members of these families exhibited SHFM phenotype with involvement of hands and feet. Genotyping using microsatellite markers mapped the families to WNT10B gene at SHFM6 on chromosome 12q13.11-q13. Subsequently, sequence analysis of WNT10B gene revealed a novel 4-bp deletion mutation (c.1165_1168delAAGT) in one family and 7-bp duplication (c.300_306dupAGGGCGG) in two other families. Structure-based analysis showed a significant conformational shift in the active binding site of mutated WNT10B (p.Lys388Glufs*36), influencing binding with Fzd8. The mutations identified in the WNT10B gene extend the body of evidence implicating it in the pathogenesis of SHFM.

Mosaic small supernumerary marker chromosome 1 at amniocentesis: prenatal diagnosis, molecular genetic analysis and literature review

We present prenatal diagnosis and molecular cytogenetic analysis of mosaic small supernumerary marker chromosome 1 [sSMC(1)]. We review the literature of sSMC(1) at amniocentesis and chromosome 1p21.1-p12 duplication syndrome. We discuss the genotype-phenotype correlation of the involved genes of ALX3, RBM15, NTNG1, SLC25A24, GPSM2, TBX15 and NOTCH2 in this case.

3q26.31-q29 duplication and 9q34.3 microdeletion associated with omphalocele, ventricular septal defect, abnormal first-trimester maternal serum screening and increased nuchal translucency: prenatal diagnosis and aCGH characterization

We present prenatal diagnosis and array comparative genomic hybridization characterization of 3q26.31-q29 duplication and 9q34.3 microdeletion in a fetus with omphalocele, ventricular septal defect, increased nuchal translucency, abnormal first-trimester maternal screening and facial dysmorphism with distinct features of the 3q duplication syndrome and Kleefstra syndrome. The 26.61-Mb duplication of 3q26.31-q29 encompasses EPHB3, CLDN1 and CLDN16, and the 972-kb deletion of 9q34.3 encompasses EHMT1. We review the literature of partial trisomy 3q associated with omphalocele and discuss the genotype-phenotype correlation in this case.

A prenatally ascertained, maternally inherited 14.8 Mb duplication of chromosomal bands Xq13.2-q21.31 associated with multiple congenital abnormalities in a male fetus

Duplications of the X chromosome are rare cytogenetic findings, and have been associated with an abnormal phenotype in the male offspring of apparently normal or near normal female carriers. We report on the prenatal diagnosis of a duplication on the long arm of chromosome X from chromosomal band Xq13.2 to q21.31 in a male fetus with increased nuchal translucency in the first trimester and polyhydramnios at 22 weeks of gestation. Amniocentesis was undertaken and cytogenetic analysis revealed additional chromosomal material in the long arm of chromosome X at position Xq13. Analysis with high resolution array CGH revealed the additional material is in fact a duplication of the region Xq13.2-q21.13. The duplication is 14.8 Mb in size and includes fourteen genes: SLC16A2, KIAA2022, ABCB7, ZDHHC15, ATRX, MAGT1, ATP7A, PGK1, TBX22, BRWD3, POU3F4, ZNF711, POF1B and CHM. Analysis of the parents revealed the mother to be a carrier of the same duplication. After elected termination of the pregnancy at 28 weeks a detailed autopsy of the fetus allowed for genotype-phenotype correlations.

Novel and recurrent mutations in the TAT gene in Tunisian families affected with Richner-Hanhart syndrome

Tyrosinemia type II, also designated as oculocutaneous tyrosinemia or Richner-Hanhart syndrome (RHS), is a very rare autosomal recessive disorder. In the present study, we report clinical features and molecular genetic investigation of the tyrosine aminotransferase (TAT) gene in two young patients, both born to consanguineous unions between first-degree cousins. These two unrelated families originated from Northern and Southern Tunisia. The clinical diagnosis was based on the observation of several complications related to Richner-Hanhart syndrome: recurrent eye redness, tearing and burning pain, photophobia, bilateral pseudodendritic keratitis, an erythematous and painful focal palmo-plantar hyperkeratosis and a mild delay of mental development. The diagnosis was confirmed by biochemical analysis. Sequencing of the TAT gene revealed the presence of a previously reported missense mutation (c.452G>A, p.Cys151Tyr) in a Tunisian family, and a novel G duplication (c.869dupG, p.Trp291Leufs 6). Early diagnosis of RHS and protein-restricted diet are crucial to reduce the risk and the severity of long-term complications of hypertyrosinemia such as intellectual disability.

Ethnic diversity and pathways to care for a first episode of psychosis in Ontario

OBJECTIVE

To examine ethnic variations in the pathways to care for persons accessing early intervention (EI) services in Ontario.

METHOD

The pathways to care and the duration of untreated psychosis were assessed for first-episode psychosis patients who entered specialized EI services in Ontario. The sample was assigned to the following ethnic classifications: the White (Caucasian), Black (African descent), and Asian (ancestry from the continent) groups, plus all the "other ethnicities" group.

RESULTS

There were 200 participants: 78% were male; 61% from the White, 15% Black, 13% Asian, and 11% were from the other ethnicities group. At the first point of contact, more participants used nonmedical contacts (12%), such as clergy and naturopathic healers, than psychologists (8%) or psychiatrists (7%). There were no ethnic differences for duration of untreated psychosis (median 22 weeks) or for initiation of help seeking by family/friends (53%), police (15%), or self (33%). After adjusting for relevant clinical and demographic factors, the Asian and other ethnicities groups were 4 and 3 times (respectively) more likely than the White or Black groups (P = .017) to use emergency room services as the first point of contact in the pathways to care. Participants from the Asian group experienced less involuntary hospitalizations (P = .023) than all the other groups. Yet overall, there were many more similarities than significant differences in the pathways to care.

CONCLUSION

EI services should monitor the pathways to care for young people of diverse ethnic backgrounds to address any disparities in accessing care.