Stephen Lynn

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Pancreatic beta cell function has been shown to decline with age in man. Depletion of mitochondrial DNA (mtDNA) copy number is associated with impaired insulin secretion in pancreatic beta cell lines, and decreased mtDNA copy number has been observed with age in skeletal muscle in man. We investigated whether mtDNA copy number decreases with age in human(More)
Duchenne muscular dystrophy (DMD) is an X-linked genetic disease, caused by the absence of the dystrophin protein. Although many novel therapies are under development for DMD, there is currently no cure and affected individuals are often confined to a wheelchair by their teens and die in their twenties/thirties. DMD is a rare disease (prevalence <5/10,000).(More)
To investigate the contribution of inherited biochemical defects to the peripheral insulin resistance of type 2 diabetes, we studied cultured skeletal muscle from 10 insulin-resistant nondiabetic first-degree relatives of type 2 diabetic families and 6 control subjects. Insulin stimulation of glucose uptake and glycogen synthesis was maximal in myoblasts.(More)
The EuroBioBank (EBB) network ( is the first operating network of biobanks in Europe to provide human DNA, cell and tissue samples as a service to the scientific community conducting research on rare diseases (RDs). The EBB was established in 2001 to facilitate access to RD biospecimens and associated data; it obtained funding from the(More)
We have defined the genetic defect in a large family first described in one of the earliest reports of suspected mitochondrial myopathy, as the mutation T14709C in the mitochondrial transfer RNA(Glu) (mt-tRNA(Glu)) gene. Extraordinarily, this mutation has attained homoplasmy (100% mutated mt-tRNA(Glu)) on at least three independent occasions in this family(More)
Aims/Hypothesis. To examine whether there is a high content of mutated mitochondrial DNA in individual pancreatic beta cells from a patient with the A3243G mitochondrial DNA mutation. Methods. Tissues were available from a patient with diabetes and the A3243G mutation including pancreatic tissue. We quantified the amount of mutated mitochondrial DNA in(More)
The transmission disequilibrium test with use of trios (an affected proband with both parents) is a robust method for assessing the role of gene variants in disease that avoids the problem of population stratification that may confound conventional case/control studies and allows the detection of parent-of-origin effects. Trios have played a major role in(More)
Variation in the calpain-10 gene (CAPN10) has been shown to be associated with type 2 diabetes in Mexican-Americans and in at least three Northern European populations. Studies in nondiabetic Pima Indians showed that one of the at-risk DNA polymorphisms, single-nucleotide polymorphism (SNP)-43, in CAPN10 was associated with insulin resistance, and(More)
For any mitochondrial DNA (mtDNA) mutation, the ratio of mutant to wild-type mtDNA (% heteroplasmy) varies across tissues, with low levels in leukocytes and high levels in postmitotic tissues (e.g., skeletal muscle). Direct sequencing is the gold-standard method used to detect novel mutations, but can only reliably detect % heteroplasmy >25%, which is rare(More)