David P. Kelsell

Bio: David P. Kelsell is an academic researcher from Queen Mary University of London. The author has contributed to research in topics: Connexin & Mutation. The author has an hindex of 57, co-authored 192 publications receiving 13827 citations. Previous affiliations of David P. Kelsell include GlaxoSmithKline & Cancer Research UK.

Germline mutations in FH predispose to dominantly inherited uterine fibroids, skin leiomyomata and papillary renal cell cancer.

Abstract: Uterine leiomyomata (fibroids) are common and clinically important tumors, but little is known about their etiology and pathogenesis. We previously mapped a gene that predisposes to multiple fibroids, cutaneous leiomyomata and renal cell carcinoma to chromosome 1q42.3-q43 (refs 4-6). Here we show, through a combination of mapping critical recombinants, identifying individuals with germline mutations and screening known and predicted transcripts, that this gene encodes fumarate hydratase, an enzyme of the tricarboxylic acid cycle. Leiomyomatosis-associated mutations are predicted to result in absent or truncated protein, or substitutions or deletions of highly conserved amino acids. Activity of fumarate hydratase is reduced in lymphoblastoid cells from individuals with leiomyomatosis. This enzyme acts as a tumor suppressor in familial leiomyomata, and its measured activity is very low or absent in tumors from individuals with leiomyomatosis. Mutations in FH also occur in the recessive condition fumarate hydratase deficiency, and some parents of people with this condition are susceptible to leiomyomata. Thus, heterozygous and homozygous or compound heterozygous mutants have very different clinical phenotypes. Our results provide clues to the pathogenesis of fibroids and emphasize the importance of mutations of housekeeping and mitochondrial proteins in the pathogenesis of common types of tumor.

Connexin 26 mutations in hereditary non-syndromic sensorineural deafness

Abstract: Severe deafness or hearing impairment is the most prevalent inherited sensory disorder, affecting about 1 in 1,000 children. Most deafness results from peripheral auditory defects that occur as a consequence of either conductive (outer or middle ear) or sensorineuronal (cochlea) abnormalities. Although a number of mutant genes have been identified that are responsible for syndromic (multiple phenotypic disease) deafness such as Waardenburg syndrome and Usher 1B syndrome, little is known about the genetic basis of non-syndromic (single phenotypic disease) deafness. Here we study a pedigree containing cases of autosomal dominant deafness and have identified a mutation in the gene encoding the gap-junction protein connexin 26 (Cx26) that segregates with the profound deafness in the family. Cx26 mutations resulting in premature stop codons were also found in three autosomal recessive non-syndromic sensorineuronal deafness pedigrees, genetically linked to chromosome 13q11-12 (DFNB1), where the Cx26 gene is localized. Immunohistochemical staining of human cochlear cells for Cx26 demonstrated high levels of expression. To our knowledge, this is the first non-syndromic sensorineural autosomal deafness susceptibility gene to be identified, which implicates Cx26 as an important component of the human cochlea.

Recessive mutation in desmoplakin disrupts desmoplakin–intermediate filament interactions and causes dilated cardiomyopathy, woolly hair and keratoderma

Abstract: Desmosomes are major cell adhesion junctions, particularly prominent in the epidermis and cardiac tissue and are important for the rigidity and strength of the cells. The desmosome consists of several proteins, of which desmoplakin is the most abundant. Here, we describe the first recessive human mutation, 7901delG, in the desmoplakin gene which causes a generalized striate keratoderma particularly affecting the palmoplantar epidermis, woolly hair and a dilated left ventricular cardiomyopathy. A number of the patients with this syndromic disorder suffer heart failure in their teenage years, resulting in early morbidity. All tested affected members of three families from Ecuador were homozygous for this mutation which produces a premature stop codon leading to a truncated desmoplakin protein missing the C domain of the tail region. Histology of the skin revealed large intercellular spaces and clustering of desmosomes at the infrequent sites of keratinocyte adhesion. Immunohistochemistry of skin from the patients showed a perinuclear localization of keratin in suprabasal keratinocytes, suggesting a collapsed intermediate filament network. This study demonstrates the importance of desmoplakin in the attachment of intermediate filaments to the desmosome. In contrast to null Desmoplakin mice which die in early development, the truncated protein due to the homozygous 7901delG mutation in humans is not embryonic lethal. This suggests that the tail domain of desmoplakin is not required for establishing tissue architecture during development.

Plectin deficiency results in muscular dystrophy with epidermolysis bullosa

Abstract: We report that mutation in the gene for plectin, a cytoskeleton–membrane anchorage protein, is a cause of autosomal recessive muscular dystrophy associated with skin blistering (epidermolysis bullosa simplex). The evidence comes from absence of plectin by antibody staining in affected individuals from four families, supportive genetic analysis (localization of the human plectin gene to chromosome 8q24.13–qter and evidence for disease segregation with markers in this region) and finally the identification of a homozygous frameshift mutation detected in plectin cDNA. Absence of the large multifunctional cytoskeleton protein plectin can simultaneously account for structural failure in both muscle and skin.

A strong candidate for the breast and ovarian cancer susceptibility gene BRCA1

Abstract: A strong candidate for the 17q-linked BRCA1 gene, which influences susceptibility to breast and ovarian cancer, has been identified by positional cloning methods. Probable predisposing mutations have been detected in five of eight kindreds presumed to segregate BRCA1 susceptibility alleles. The mutations include an 11-base pair deletion, a 1-base pair insertion, a stop codon, a missense substitution, and an inferred regulatory mutation. The BRCA1 gene is expressed in numerous tissues, including breast and ovary, and encodes a predicted protein of 1863 amino acids. This protein contains a zinc finger domain in its amino-terminal region, but is otherwise unrelated to previously described proteins. Identification of BRCA1 should facilitate early diagnosis of breast and ovarian cancer susceptibility in some individuals as well as a better understanding of breast cancer biology.