𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Parental origin and somatic mosaicism of PHOX2B mutations in Congenital Central Hypoventilation Syndrome

✍ Scribed by Sara Parodi; Tiziana Bachetti; Francesca Lantieri; Marco Di Duca; Giuseppe Santamaria; Giancarlo Ottonello; Ivana Matera; Roberto Ravazzolo; Isabella Ceccherini


Publisher
John Wiley and Sons
Year
2007
Tongue
English
Weight
191 KB
Volume
29
Category
Article
ISSN
1059-7794

No coin nor oath required. For personal study only.

✦ Synopsis


Communicated by Michel Goossens

Heterozygous polyalanine repeat expansions of PHOX2B have been associated with Congenital Central Hypoventilation Syndrome, a rare neurocristopathy characterized by absence of adequate control of respiration during sleep. Here we report a PHOX2B mutational screening in 63 CCHS patients, 58 of whom presenting with poly-A expansions or frameshift, missense and nonsense mutations. To assess a somatic or germline occurrence of poly-A length variations, the relative amounts of mutant and wild type alleles have been quantified in 20 selected CCHS patients presenting with an expansion, and in their parents. Somatic mosaicism was shown in four parents, while no mosaic was found among CCHS patients. Moreover, while co-segregation analysis of the PHOX2B poly-A expansions with selected marker alleles in the same 20 CCHS trios has not demonstrated any parent-oforigin effect of the mutations, it has provided further clues to clarify the molecular mechanism underlying the expansion occurrence. Finally, the segregation of PHOX2B poly-A anomalous tracts within family members has allowed us to exclude tendency of polymorphic variations towards expansion. This strengthens the notion that expanded polyalanine tracts, identified as frequent disease-causing mutations also in other human diseases, are mitotically and meiotically stable.


πŸ“œ SIMILAR VOLUMES


Homozygous mutation of the PHOX2B gene i
✍ Delphine Trochet; LoΓ―c de Pontual; Maria Helena EstΓͺvao; Yves Mathieu; Arnold Mu πŸ“‚ Article πŸ“… 2008 πŸ› John Wiley and Sons 🌐 English βš– 495 KB

Homozygosity for a dominant allele is relatively rare and preferentially observed in communities with high inbreeding. According to the definition of true dominance, similar phenotypes should be observed in patients heterozygous and homozygous for a dominant mutation. However, the homozygous phenoty

In Vitro studies of non poly alanine PHO
✍ Delphine Trochet; Yves Mathieu; LoΓ―c de Pontual; Ravi Savarirayan; Arnold Munnic πŸ“‚ Article πŸ“… 2009 πŸ› John Wiley and Sons 🌐 English βš– 550 KB

A wide range of autonomic dysfunctions, i.e. Central Hypoventilation Syndromes, Hirschsprung disease and Tumours of the Sympathetic Nervous System have been ascribed to heterozygous PHOX2B mutations in man. The PHOX2B mutations reported include polyalanine expansions in a 20 alanines tract, missense