Abstract
Context: P450 oxidoreductase (POR) deficiency causes disordered steroidogenesis; severe mutations cause genital ambiguity in both sexes plus the Antley-Bixler skeletal malformation syndrome, whereas mild mutations can cause adult infertility. Objective: We describe four patients with POR deficiency and identify and characterize the activities of their mutations. A 46,XY male with micropenis and two 46,XX female infants with genital ambiguity presented with skeletal malformations, and a 46,XX adolescent presented with primary amenorrhea, elevated 17α-hydroxyprogesterone, and low sex steroids. Methods: The coding regions of the POR gene were sequenced, and the identified mutations were recreated in human POR cDNA expression vectors lacking 27 N-terminal residues. POR and human P450c17 were expressed in bacteria. POR activity was measured by four assays: reduction of cytochrome c, oxidation of reduced nicotinamide adenine dinucleotide phosphate, and support of the 17α-hydroxylase and 17,20 lyase activities of P450c17. Results: All four patients were compound heterozygotes for POR mutations, including five novel mutations: L577R, N185K, delE217, and frameshift mutations 1363delC and 697-698insGAAC. N185K and delE217 lacked measurable activity in the assays based on P450c17 but retained partial activity in the assays based on cytochrome c. As assessed by Vmax/Km, L577R supported 46% of 17α-hydroxylase activity but only 27% of 17,20 lyase activity. Computational modeling of these novel mutants revealed the structural basis for their reduced or absent activities. Conclusion: These patients illustrate the broad clinical spectrum of POR deficiency, including amenorrhea and infertility as the sole manifestation. POR assays based on P450c17 correlate well with hormonal and clinical phenotypes.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 4992-5000 |
| Number of pages | 9 |
| Journal | Journal of Clinical Endocrinology and Metabolism |
| Volume | 94 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 2009 |
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ASJC Scopus subject areas
- Biochemistry
- Clinical Biochemistry
- Endocrinology
- Biochemistry, medical
- Endocrinology, Diabetes and Metabolism
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Clinical, genetic, and enzymatic characterization of P450 oxidoreductase deficiency in four patients. / Sahakitrungruang, Taninee; Huang, Ningwu; Tee, Meng Kian; Agrawal, Vishal; Russell, William E.; Crock, Patricia; Murphy, Nuala; Migeon, Claude J.; Miller, Walter L.
In: Journal of Clinical Endocrinology and Metabolism, Vol. 94, No. 12, 12.2009, p. 4992-5000.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Clinical, genetic, and enzymatic characterization of P450 oxidoreductase deficiency in four patients
AU - Sahakitrungruang, Taninee
AU - Huang, Ningwu
AU - Tee, Meng Kian
AU - Agrawal, Vishal
AU - Russell, William E.
AU - Crock, Patricia
AU - Murphy, Nuala
AU - Migeon, Claude J.
AU - Miller, Walter L.
PY - 2009/12
Y1 - 2009/12
N2 - Context: P450 oxidoreductase (POR) deficiency causes disordered steroidogenesis; severe mutations cause genital ambiguity in both sexes plus the Antley-Bixler skeletal malformation syndrome, whereas mild mutations can cause adult infertility. Objective: We describe four patients with POR deficiency and identify and characterize the activities of their mutations. A 46,XY male with micropenis and two 46,XX female infants with genital ambiguity presented with skeletal malformations, and a 46,XX adolescent presented with primary amenorrhea, elevated 17α-hydroxyprogesterone, and low sex steroids. Methods: The coding regions of the POR gene were sequenced, and the identified mutations were recreated in human POR cDNA expression vectors lacking 27 N-terminal residues. POR and human P450c17 were expressed in bacteria. POR activity was measured by four assays: reduction of cytochrome c, oxidation of reduced nicotinamide adenine dinucleotide phosphate, and support of the 17α-hydroxylase and 17,20 lyase activities of P450c17. Results: All four patients were compound heterozygotes for POR mutations, including five novel mutations: L577R, N185K, delE217, and frameshift mutations 1363delC and 697-698insGAAC. N185K and delE217 lacked measurable activity in the assays based on P450c17 but retained partial activity in the assays based on cytochrome c. As assessed by Vmax/Km, L577R supported 46% of 17α-hydroxylase activity but only 27% of 17,20 lyase activity. Computational modeling of these novel mutants revealed the structural basis for their reduced or absent activities. Conclusion: These patients illustrate the broad clinical spectrum of POR deficiency, including amenorrhea and infertility as the sole manifestation. POR assays based on P450c17 correlate well with hormonal and clinical phenotypes.
AB - Context: P450 oxidoreductase (POR) deficiency causes disordered steroidogenesis; severe mutations cause genital ambiguity in both sexes plus the Antley-Bixler skeletal malformation syndrome, whereas mild mutations can cause adult infertility. Objective: We describe four patients with POR deficiency and identify and characterize the activities of their mutations. A 46,XY male with micropenis and two 46,XX female infants with genital ambiguity presented with skeletal malformations, and a 46,XX adolescent presented with primary amenorrhea, elevated 17α-hydroxyprogesterone, and low sex steroids. Methods: The coding regions of the POR gene were sequenced, and the identified mutations were recreated in human POR cDNA expression vectors lacking 27 N-terminal residues. POR and human P450c17 were expressed in bacteria. POR activity was measured by four assays: reduction of cytochrome c, oxidation of reduced nicotinamide adenine dinucleotide phosphate, and support of the 17α-hydroxylase and 17,20 lyase activities of P450c17. Results: All four patients were compound heterozygotes for POR mutations, including five novel mutations: L577R, N185K, delE217, and frameshift mutations 1363delC and 697-698insGAAC. N185K and delE217 lacked measurable activity in the assays based on P450c17 but retained partial activity in the assays based on cytochrome c. As assessed by Vmax/Km, L577R supported 46% of 17α-hydroxylase activity but only 27% of 17,20 lyase activity. Computational modeling of these novel mutants revealed the structural basis for their reduced or absent activities. Conclusion: These patients illustrate the broad clinical spectrum of POR deficiency, including amenorrhea and infertility as the sole manifestation. POR assays based on P450c17 correlate well with hormonal and clinical phenotypes.
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U2 - 10.1210/jc.2009-1460
DO - 10.1210/jc.2009-1460
M3 - Article
C2 - 19837910
AN - SCOPUS:73249131251
VL - 94
SP - 4992
EP - 5000
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
SN - 0021-972X
IS - 12
ER -