| 1. |
- Porrmann, Joseph, et al.
(författare)
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Novel PRPS1 gain-of-function mutation in a patient with congenital hyperuricemia and facial anomalies
- 2017
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Ingår i: American Journal of Medical Genetics. Part A. - : WILEY. - 1552-4825 .- 1552-4833. ; 173:10, s. 2736-2742
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Tidskriftsartikel (refereegranskat)abstract
- Phosphoribosylpyrophosphate synthetase (PRPPS) superactivity (OMIM 300661) is a rare inborn error of purine metabolism that is caused by gain-of-function mutations in the X-chromosomal gene PRPS1 (Xq22.3). Clinical characteristics include congenital hyperuricemia and hyperuricosuria, gouty arthritis, urolithiasis, developmental delay, hypotonia, recurrent infections, short stature, and hearing loss. Only eight families with PRPPS superactivity and PRPS1 gain-of-function mutations have been reported to date. We report on a 7-year-old boy with congenital hyperuricemia, urolithiasis, developmental delay, short stature, hypospadias, and facial dysmorphisms. His mother also suffered from hyperuricemia that was diagnosed at age 13 years. A novel PRPS1 missense mutation (c.573G>C, p.[Leu191Phe]) was detected in the proband and his mother. Enzyme activity analysis confirmed superactivity of PRPP synthetase. Analysis of the crystal structure of human PRPPS suggests that the Leu191Phe mutation affects the architecture of both allosteric sites, thereby preventing the allosteric inhibition of the enzyme. The family reported here broadens the clinical spectrum of PRPPS superactivity and indicates that this rare metabolic disorder might be associated with a recognizable facial gestalt.
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| 2. |
- Saetre, Peter, et al.
(författare)
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Methylenetetrahydrofolate Reductase (MTHFR) C677T and A1298C Polymorphisms and Age of Onset in Schizophrenia : A Combined Analysis of Independent Samples
- 2011
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Ingår i: American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics. - : Wiley. - 1552-4841. ; 156B156:2, s. 215-224
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Tidskriftsartikel (refereegranskat)abstract
- Methylenetetrahydrofolate reductase (MTHFR) is involved in the one-carbon cycle, which is of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes two common polymorphisms (rs1801133 or C677T; rs1801131 or A1298C) which both alter enzyme activity. The T-allele of the C677T polymorphism has recently been associated with earlier age at onset of schizophrenia. In the present study we examined the association between the MTHFR C677T and A1298C polymorphisms and age at onset of schizophrenia in twelve samples consisting of 3,213 unrelated schizophrenia patients, including the original Scandinavian sample. There was no consistent relationship between MTHFR C677T, A1298C or combined 677T/1298C carriers and age of onset in schizophrenia when the results of each study were combined using meta-analysis. The present results suggest that the investigated MTHFR polymorphisms do not influence age of onset in schizophrenia.
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