Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype–phenotype correlations, codon bias and dominant-negative effects

Fadil M. Hannan, Sarah A. Howles, Angela Rogers, Treena Cranston, Caroline M. Gorvin, Valerie N. Babinsky, Anita A. Reed, Clare E. Thakker, Detlef Bockenhauer, Rosalind S. Brown, John M. Connell, Jacqueline Cook, Ken Darzy, Sarah Ehtisham, Una Graham, Tony Hulse, Steven J. Hunter, Louise Izatt, Dhavendra Kumar, Malachi J. McKenna & 16 others John A. McKnight, Patrick J. Morrison, M. Zulf Mughal, Domhnall O'Halloran, Simon H. Pearce, Mary E. Porteous, Mushtaqur Rahman, Tristan Richardson, Robert Robinson, Isabelle Scheers, Haroon Siddique, William G. van't Hoff, Timothy Wang, Michael P. Whyte, M. Andrew Nesbit, Rajesh V. Thakker

Research output: Contribution to journalArticle

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Abstract

The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasmamembrane constituents such as the calcium-sensing receptor (CaSR).Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium(Ca2+ o) homeostasis. To elucidate the role ofAP2σ2 in Ca2+ o regulation,we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising5 Arg15Cys, 4 Arg15His and 8 Arg15Leumutations. A genotype–phenotype correlationwas observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR,whichwas ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively,for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype–phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.
LanguageEnglish
Article numberddv226
Pages5079-5092
Number of pages13
JournalHuman Molecular Genetics
Volume24
Issue number18
DOIs
Publication statusPublished - 15 Sep 2015

Fingerprint

Sigma Factor
Genetic Association Studies
Codon
Calcium-Sensing Receptors
Mutation
Proteins
Calcium
Phenotype
Magnesium
Creatinine
Type 3 Familial benign hypercalcemia
Clathrin
Hypercalcemia
Endocytosis
Serum
Signal Transduction
Homeostasis
Genotype
Sensitivity and Specificity

Keywords

  • Hypercalcaemia
  • mutation
  • genotype-phenotype

Cite this

Hannan, Fadil M. ; Howles, Sarah A. ; Rogers, Angela ; Cranston, Treena ; Gorvin, Caroline M. ; Babinsky, Valerie N. ; Reed, Anita A. ; Thakker, Clare E. ; Bockenhauer, Detlef ; Brown, Rosalind S. ; Connell, John M. ; Cook, Jacqueline ; Darzy, Ken ; Ehtisham, Sarah ; Graham, Una ; Hulse, Tony ; Hunter, Steven J. ; Izatt, Louise ; Kumar, Dhavendra ; McKenna, Malachi J. ; McKnight, John A. ; Morrison, Patrick J. ; Mughal, M. Zulf ; O'Halloran, Domhnall ; Pearce, Simon H. ; Porteous, Mary E. ; Rahman, Mushtaqur ; Richardson, Tristan ; Robinson, Robert ; Scheers, Isabelle ; Siddique, Haroon ; van't Hoff, William G. ; Wang, Timothy ; Whyte, Michael P. ; Nesbit, M. Andrew ; Thakker, Rajesh V. / Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype–phenotype correlations, codon bias and dominant-negative effects. In: Human Molecular Genetics. 2015 ; Vol. 24, No. 18. pp. 5079-5092.
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title = "Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype–phenotype correlations, codon bias and dominant-negative effects",
abstract = "The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasmamembrane constituents such as the calcium-sensing receptor (CaSR).Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium(Ca2+ o) homeostasis. To elucidate the role ofAP2σ2 in Ca2+ o regulation,we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising5 Arg15Cys, 4 Arg15His and 8 Arg15Leumutations. A genotype–phenotype correlationwas observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR,whichwas ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86{\%}, respectively,for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype–phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.",
keywords = "Hypercalcaemia, mutation, genotype-phenotype",
author = "Hannan, {Fadil M.} and Howles, {Sarah A.} and Angela Rogers and Treena Cranston and Gorvin, {Caroline M.} and Babinsky, {Valerie N.} and Reed, {Anita A.} and Thakker, {Clare E.} and Detlef Bockenhauer and Brown, {Rosalind S.} and Connell, {John M.} and Jacqueline Cook and Ken Darzy and Sarah Ehtisham and Una Graham and Tony Hulse and Hunter, {Steven J.} and Louise Izatt and Dhavendra Kumar and McKenna, {Malachi J.} and McKnight, {John A.} and Morrison, {Patrick J.} and Mughal, {M. Zulf} and Domhnall O'Halloran and Pearce, {Simon H.} and Porteous, {Mary E.} and Mushtaqur Rahman and Tristan Richardson and Robert Robinson and Isabelle Scheers and Haroon Siddique and {van't Hoff}, {William G.} and Timothy Wang and Whyte, {Michael P.} and Nesbit, {M. Andrew} and Thakker, {Rajesh V.}",
year = "2015",
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doi = "10.1093/hmg/ddv226",
language = "English",
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journal = "Human Molecular Genetics",
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Hannan, FM, Howles, SA, Rogers, A, Cranston, T, Gorvin, CM, Babinsky, VN, Reed, AA, Thakker, CE, Bockenhauer, D, Brown, RS, Connell, JM, Cook, J, Darzy, K, Ehtisham, S, Graham, U, Hulse, T, Hunter, SJ, Izatt, L, Kumar, D, McKenna, MJ, McKnight, JA, Morrison, PJ, Mughal, MZ, O'Halloran, D, Pearce, SH, Porteous, ME, Rahman, M, Richardson, T, Robinson, R, Scheers, I, Siddique, H, van't Hoff, WG, Wang, T, Whyte, MP, Nesbit, MA & Thakker, RV 2015, 'Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype–phenotype correlations, codon bias and dominant-negative effects', Human Molecular Genetics, vol. 24, no. 18, ddv226, pp. 5079-5092. https://doi.org/10.1093/hmg/ddv226

Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype–phenotype correlations, codon bias and dominant-negative effects. / Hannan, Fadil M.; Howles, Sarah A.; Rogers, Angela; Cranston, Treena; Gorvin, Caroline M.; Babinsky, Valerie N.; Reed, Anita A.; Thakker, Clare E.; Bockenhauer, Detlef; Brown, Rosalind S.; Connell, John M.; Cook, Jacqueline; Darzy, Ken; Ehtisham, Sarah; Graham, Una; Hulse, Tony; Hunter, Steven J.; Izatt, Louise; Kumar, Dhavendra; McKenna, Malachi J.; McKnight, John A.; Morrison, Patrick J.; Mughal, M. Zulf; O'Halloran, Domhnall; Pearce, Simon H.; Porteous, Mary E.; Rahman, Mushtaqur; Richardson, Tristan; Robinson, Robert; Scheers, Isabelle; Siddique, Haroon; van't Hoff, William G.; Wang, Timothy; Whyte, Michael P.; Nesbit, M. Andrew; Thakker, Rajesh V.

In: Human Molecular Genetics, Vol. 24, No. 18, ddv226, 15.09.2015, p. 5079-5092.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype–phenotype correlations, codon bias and dominant-negative effects

AU - Hannan, Fadil M.

AU - Howles, Sarah A.

AU - Rogers, Angela

AU - Cranston, Treena

AU - Gorvin, Caroline M.

AU - Babinsky, Valerie N.

AU - Reed, Anita A.

AU - Thakker, Clare E.

AU - Bockenhauer, Detlef

AU - Brown, Rosalind S.

AU - Connell, John M.

AU - Cook, Jacqueline

AU - Darzy, Ken

AU - Ehtisham, Sarah

AU - Graham, Una

AU - Hulse, Tony

AU - Hunter, Steven J.

AU - Izatt, Louise

AU - Kumar, Dhavendra

AU - McKenna, Malachi J.

AU - McKnight, John A.

AU - Morrison, Patrick J.

AU - Mughal, M. Zulf

AU - O'Halloran, Domhnall

AU - Pearce, Simon H.

AU - Porteous, Mary E.

AU - Rahman, Mushtaqur

AU - Richardson, Tristan

AU - Robinson, Robert

AU - Scheers, Isabelle

AU - Siddique, Haroon

AU - van't Hoff, William G.

AU - Wang, Timothy

AU - Whyte, Michael P.

AU - Nesbit, M. Andrew

AU - Thakker, Rajesh V.

PY - 2015/9/15

Y1 - 2015/9/15

N2 - The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasmamembrane constituents such as the calcium-sensing receptor (CaSR).Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium(Ca2+ o) homeostasis. To elucidate the role ofAP2σ2 in Ca2+ o regulation,we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising5 Arg15Cys, 4 Arg15His and 8 Arg15Leumutations. A genotype–phenotype correlationwas observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR,whichwas ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively,for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype–phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.

AB - The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasmamembrane constituents such as the calcium-sensing receptor (CaSR).Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium(Ca2+ o) homeostasis. To elucidate the role ofAP2σ2 in Ca2+ o regulation,we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising5 Arg15Cys, 4 Arg15His and 8 Arg15Leumutations. A genotype–phenotype correlationwas observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR,whichwas ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively,for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype–phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.

KW - Hypercalcaemia

KW - mutation

KW - genotype-phenotype

U2 - 10.1093/hmg/ddv226

DO - 10.1093/hmg/ddv226

M3 - Article

VL - 24

SP - 5079

EP - 5092

JO - Human Molecular Genetics

T2 - Human Molecular Genetics

JF - Human Molecular Genetics

SN - 0964-6906

IS - 18

M1 - ddv226

ER -