title: Novel Mutations in the PC Gene in Patients with Type B Pyruvate Carboxylase Deficiency.
abstract: We have investigated seven patients with the type B form of pyruvate carboxylase (PC) deficiency. Mutation analysis revealed eight mutations, all novel. In a patient with exon skipping on cDNA analysis, we identified a homozygous mutation located in a potential branch point sequence, the first possible branch point mutation in PC. Two patients were homozygous for missense mutations (with normal protein amounts on western blot analysis), and two patients were homozygous for nonsense mutations. In addition, a duplication of one base pair was found in a patient who also harboured a splice site mutation. Another splice site mutation led to the activation of a cryptic splice site, shown by cDNA analysis.All patients reported until now with at least one missense mutation have had the milder type A form of PC deficiency. We thus report for the first time two patients with homozygous missense mutations with the severe type B deficiency, clinically indistinguishable from other patients with type B form of PC deficiency.The mutations found here are novel; it is noteworthy that four Turkish patients did not have any mutations in common, despite the rarity of PC deficiency. There is thus no evidence for recurrent mutations in the Turkish or other populations.
authors: Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark. elsebet.ostergaard@dadlnet.dk.
authors: Elsebet
authors: E
authors: Ostergaard
authors: Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.
authors: Morten
authors: M
authors: Duno
authors: Center of Applied Human Molecular Genetics, Kennedy Center, Glostrup, Denmark.
authors: Lisbeth Birk
authors: LB
authors: Møller
authors: Department of Pediatrics, Section of Nutrition & Metabolism, Hacettepe University Faculty of Medicine, Ankara, Turkey.
authors: H Serap
authors: HS
authors: Kalkanoglu-Sivri
authors: Department of Pediatrics, Section of Nutrition & Metabolism, Hacettepe University Faculty of Medicine, Ankara, Turkey.
authors: Ali
authors: A
authors: Dursun
authors: Department of Pediatrics, School of Medicine, Kirikkale University, Kirikkale, Turkey.
authors: Didem
authors: D
authors: Aliefendioglu
authors: Department of Pediatrics, Roskilde University Hospital, Roskilde, Denmark.
authors: Helle
authors: H
authors: Leth
authors: Department of Pediatrics, Odense University Hospital, Odense, Denmark.
authors: Marianne
authors: M
authors: Dahl
authors: Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.
authors: Ernst
authors: E
authors: Christensen
authors: Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark.
authors: Flemming
authors: F
authors: Wibrand