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Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling

AIMS/HYPOTHESIS: Genetic insulin receptoropathies are a rare cause of severe insulin resistance. We identified the Ile119Met missense mutation in the insulin receptor INSR gene, previously reported in a Yemeni kindred, in four unrelated patients with Somali ancestry. We aimed to investigate a possib...

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Autores principales: Raffan, E., Soos, M. A., Rocha, N., Tuthill, A., Thomsen, A. R., Hyden, C. S., Gregory, J. W., Hindmarsh, P., Dattani, M., Cochran, E., Al Kaabi, J., Gorden, P., Barroso, I., Morling, N., O’Rahilly, S., Semple, R. K.
Formato: Texto
Lenguaje:English
Publicado: Springer-Verlag 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3071941/
https://www.ncbi.nlm.nih.gov/pubmed/21318406
http://dx.doi.org/10.1007/s00125-011-2066-z
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author Raffan, E.
Soos, M. A.
Rocha, N.
Tuthill, A.
Thomsen, A. R.
Hyden, C. S.
Gregory, J. W.
Hindmarsh, P.
Dattani, M.
Cochran, E.
Al Kaabi, J.
Gorden, P.
Barroso, I.
Morling, N.
O’Rahilly, S.
Semple, R. K.
author_facet Raffan, E.
Soos, M. A.
Rocha, N.
Tuthill, A.
Thomsen, A. R.
Hyden, C. S.
Gregory, J. W.
Hindmarsh, P.
Dattani, M.
Cochran, E.
Al Kaabi, J.
Gorden, P.
Barroso, I.
Morling, N.
O’Rahilly, S.
Semple, R. K.
author_sort Raffan, E.
collection PubMed
description AIMS/HYPOTHESIS: Genetic insulin receptoropathies are a rare cause of severe insulin resistance. We identified the Ile119Met missense mutation in the insulin receptor INSR gene, previously reported in a Yemeni kindred, in four unrelated patients with Somali ancestry. We aimed to investigate a possible genetic founder effect, and to study the mechanism of loss of function of the mutant receptor. METHODS: Biochemical profiling and DNA haplotype analysis of affected patients were performed. Insulin receptor expression in lymphoblastoid cells from a homozygous p.Ile119Met INSR patient, and in cells heterologously expressing the mutant receptor, was examined. Insulin binding, insulin-stimulated receptor autophosphorylation, and cooperativity and pH dependency of insulin dissociation were also assessed. RESULTS: All patients had biochemical profiles pathognomonic of insulin receptoropathy, while haplotype analysis revealed the putative shared region around the INSR mutant to be no larger than 28 kb. An increased insulin proreceptor to β subunit ratio was seen in patient-derived cells. Steady state insulin binding and insulin-stimulated autophosphorylation of the mutant receptor was normal; however it exhibited decreased insulin dissociation rates with preserved cooperativity, a difference accentuated at low pH. CONCLUSIONS/INTERPRETATION: The p.Ile119Met INSR appears to have arisen around the Horn of Africa, and should be sought first in severely insulin resistant patients with ancestry from this region. Despite collectively compelling genetic, clinical and biochemical evidence for its pathogenicity, loss of function in conventional in vitro assays is subtle, suggesting mildly impaired receptor recycling only. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00125-011-2066-z) contains supplementary material, which is available to authorised users.
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spelling pubmed-30719412011-05-18 Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling Raffan, E. Soos, M. A. Rocha, N. Tuthill, A. Thomsen, A. R. Hyden, C. S. Gregory, J. W. Hindmarsh, P. Dattani, M. Cochran, E. Al Kaabi, J. Gorden, P. Barroso, I. Morling, N. O’Rahilly, S. Semple, R. K. Diabetologia Article AIMS/HYPOTHESIS: Genetic insulin receptoropathies are a rare cause of severe insulin resistance. We identified the Ile119Met missense mutation in the insulin receptor INSR gene, previously reported in a Yemeni kindred, in four unrelated patients with Somali ancestry. We aimed to investigate a possible genetic founder effect, and to study the mechanism of loss of function of the mutant receptor. METHODS: Biochemical profiling and DNA haplotype analysis of affected patients were performed. Insulin receptor expression in lymphoblastoid cells from a homozygous p.Ile119Met INSR patient, and in cells heterologously expressing the mutant receptor, was examined. Insulin binding, insulin-stimulated receptor autophosphorylation, and cooperativity and pH dependency of insulin dissociation were also assessed. RESULTS: All patients had biochemical profiles pathognomonic of insulin receptoropathy, while haplotype analysis revealed the putative shared region around the INSR mutant to be no larger than 28 kb. An increased insulin proreceptor to β subunit ratio was seen in patient-derived cells. Steady state insulin binding and insulin-stimulated autophosphorylation of the mutant receptor was normal; however it exhibited decreased insulin dissociation rates with preserved cooperativity, a difference accentuated at low pH. CONCLUSIONS/INTERPRETATION: The p.Ile119Met INSR appears to have arisen around the Horn of Africa, and should be sought first in severely insulin resistant patients with ancestry from this region. Despite collectively compelling genetic, clinical and biochemical evidence for its pathogenicity, loss of function in conventional in vitro assays is subtle, suggesting mildly impaired receptor recycling only. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00125-011-2066-z) contains supplementary material, which is available to authorised users. Springer-Verlag 2011-02-12 2011 /pmc/articles/PMC3071941/ /pubmed/21318406 http://dx.doi.org/10.1007/s00125-011-2066-z Text en © The Author(s) 2011 https://creativecommons.org/licenses/by-nc/4.0/ This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
spellingShingle Article
Raffan, E.
Soos, M. A.
Rocha, N.
Tuthill, A.
Thomsen, A. R.
Hyden, C. S.
Gregory, J. W.
Hindmarsh, P.
Dattani, M.
Cochran, E.
Al Kaabi, J.
Gorden, P.
Barroso, I.
Morling, N.
O’Rahilly, S.
Semple, R. K.
Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling
title Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling
title_full Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling
title_fullStr Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling
title_full_unstemmed Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling
title_short Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling
title_sort founder effect in the horn of africa for an insulin receptor mutation that may impair receptor recycling
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3071941/
https://www.ncbi.nlm.nih.gov/pubmed/21318406
http://dx.doi.org/10.1007/s00125-011-2066-z
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