De novo interstitial deletion of 1q32.2-q32.3 including the entire IRF6 gene in a patient with oral cleft and other dysmorphic features

BACKGROUND

Microdeletion of the Van der Woude syndrome (VWS) critical region is a relatively rare event, and only a few cases have been reported in the medical literature. The extent of the deletion and the genotype-phenotype correlation are 2 crucial issues.

METHODS AND RESULTS

During analysis of the VWS critical region in 95 families with an isolated cleft of the lip with or without cleft palate, we found a de novo interstitial deletion of 1q32.2-q32.3 in a patient with cleft lip and other dysmorphic features. The present case showed new proximal and distal end breakpoints compared to those previously reported. The results of a short tandem repeat analysis was confirmed using high resolution array-based comparative genomic hybridization and showed an interstitial deletion of approximately 2.98 Mb which involved 25 genes, including the entire IRF6 gene. Direct sequencing of the non-deleted allele of the IRF6 gene did not show any mutation, which supports a haploinsufficiency mechanism of the IRF6 gene in the development of the oral cleft.

CONCLUSION

The present report adds to the collective knowledge that oral cleft is a major clinical feature of the 1q32.2-q32.3 deletion.

Contribution of 6p24 to non-syndromic cleft lip and palate in a Malay population: association of variants in OFC1

Non-syndromic cleft lip, with or without cleft palate, is a heterogeneous, complex disease with a high incidence in the Asian population. Several association studies have been done on cleft candidate genes, but no reports have been published thus far on the Orofacial Cleft 1 (OFC1) genomic region in an Asian population. This study investigated the association between the OFC1 genomic region and non-syndromic cleft lip with or without cleft palate in 90 Malay father-mother-offspring trios. Results showed a preferential over-transmission of a 101-bp allele of marker D6S470 in the allele- and haplotype-based transmission disequilibrium test (TDT), as well as an excess of maternal transmission. However, no significant p-value was found for a maternal genotype effect in a log-linear model, although single and double doses of the 101-bp allele showed a slightly increased cleft risk (RR = 1.37, 95% CI, 0.527-3.4, p-value = 0.516). Carrying two copies of the 101-bp allele was significantly associated with an increased cleft risk (RR = 2.53, 95% CI, 1.06-6.12, p-value = 0.035). In conclusion, we report evidence of the contribution of the OFC1 genomic region to the etiology of clefts in a Malay population.

Complex chromosomal rearrangement involving chromosomes 1, 4 and 22 in an infertile male: case report and literature review

Here we describe a rare case of an apparently balanced karyotype of 46, XY, t(1;22;4)(p22.3;q11.1;q31.1) in a infertile male with oligoastenoteratozoospermia (OAT). He was the second patient with complex chromosomal rearrangement (CCR) referred to our center because of infertility. We also review reports on 24 males carrying CCRs with spermatogenesis failure or a malformed child, to provide information on the reproductive outcome of male CCR carriers.