Chromosome 9p terminal deletion in nine Egyptian patients and narrowing of the critical region for trigonocephaly.

BACKGROUND: This study aimed to delineate the clinical phenotype of patients with 9p deletions, pinpoint the chromosomal breakpoints, and identify the critical region for trigonocephaly, which is a frequent finding in 9p terminal deletion. METHODS: We investigated a cohort of nine patients with chromosome 9p terminal deletions who all displayed developmental delay, intellectual disability, hypotonia, and dysmorphic features. Of them, eight had trigonocephaly, seven had brain anomalies, seven had autistic manifestations, seven had fair hair, and six had a congenital heart defect (CHD). RESULTS: Karyotyping revealed 9p terminal deletion in all patients, and patients 8 and 9 had additional duplication of other chromosomal segments. We used six bacterial artificial chromosome (BAC) clones that could identify the breakpoints at 17-20 Mb from the 9p terminus. Array CGH identified the precise extent of the deletion in six patients; the deleted regions ranged from 16 to 18.8 Mb in four patients, patient 8 had an 11.58 Mb deletion and patient 9 had a 2.3 Mb deletion. CONCLUSION: The gene deletion in the 9p24 region was insufficient to cause ambiguous genitalia because six of the nine patients had normal genitalia. We suggest that the critical region for trigonocephaly lies between 11,575 and 11,587 Mb from the chromosome 9p terminus. To the best of our knowledge, this is the minimal critical region reported for trigonocephaly in 9p deletion syndrome, and it warrants further delineation.

Correction to: Vitamin D status and vitamin D receptor gene polymorphism in Saudi children with acute lower respiratory tract infection.

The correct affiliations for all authors are as given below.

Vitamin D status and vitamin D receptor gene polymorphism in Saudi children with acute lower respiratory tract infection.

There is a significant association exists between vitamin D deficiencies, low respiratory tract infections, and certain types of VDR gene polymorphism. Various studies are being conducted to prove any such link between the different clinical conditions due to disturbed vitamin D regulation and VDR gene polymorphisms. The present study analyzed the presence of vitamin D receptor (VDR) gene polymorphisms (ApaI and TaqI) in Saudi pediatric patient suffering from acute lower respiratory tract infection (ALRTI) cases. Fifty children (50) with ALRTI admitted at King Saud University Medical City, Riyadh/Saudi Arabia were included in addition to seventy-three (73) apparently healthy children who were considered as the control group. Genomic DNA from whole blood was extracted and subjected to polymerase chain reaction (PCR) targeting TaqI and ApaI VDR polymorphisms. RFLP-PCR genotyping was performed to determine the allelic frequency within the VDR gene. In the whole sample, the allelic frequency of ApaI polymorphism in the VDR gene was 58.5%, 17.9%, and 23.6% for AA, Aa, and aa respectively (p = 0.11), while it was 48%, 19%, and 33% for TT, Tt, and tt respectively (p = 0.33) with regards to the frequency of TaqI polymorphism in the VDR gene. VDR ApaI Aa and aa genotypes and VDR TaqI Tt and tt genotypes were not associated with increased risk of ALRTI in children (OR 0.87, 95% CI 0.33-2.28, p = 0.77; OR 0.56, 95% CI 0.23-1.4, p = 0.21; OR 1.15, 95% CI 0.44-2.99, p = 0.77; OR 0.73, 95% CI 0.32-1.68, p = 0.46 respectively). To conclude, neither vitamin D status nor VDR gene polymorphisms such as ApaI and TaqI is associated with increased susceptibility to ALRTI. Linkage disequilibrium was not detected between ApaI and TaqI VDR gene polymorphisms as in the case of serum vitamin D status in ALRTI patients versus apparent healthy children.