TY - JOUR
T1 - A de novo unequal cross-over mutation between CYP11B1 and CYP11B2 genes causes familial hyperaldosteronism type I
AU - Carvajal, C. A.
AU - Stehr, C. B.
AU - González, P. A.
AU - Riquelme, E. M.
AU - Montero, T.
AU - Santos, M. J.
AU - Kalergis, A. M.
AU - Fardella, Carlos E.
N1 - Funding Information:
This work was supported by Chilean “FONDECYT 1070876, 1100356” (CAC, CEF), “FONDECYT 1070352” (AMK), FONDEF D08i1087and “Millennium Nucleus of Immunology and Immunotherapy (P07/088-F)” grants (PAG, EMR, CEF, AMK). CAC is a fellow from Comision Nacional de In-vestigacion Cientifica y Tecnologica de Chile.
PY - 2011/2
Y1 - 2011/2
N2 - Familial hyperaldosteronism type I (FH-I) is an autosomal dominant disorder caused by an unequal cross-over of the gene encoding steroid 11βhydroxylase (CYP11B1) and aldosterone synthase (CYP11B2), giving rise to a chimeric CYP11B1/CYP11B2 gene that displays aldosterone synthase activity regulated by ACTH instead of angiotensin II. Aim: To report an unprecedented case of a de novo unequal cross-over mutation between CYP11B1 and CYP11B2 genes causing FH-I. Patients and methods: The index case is a 45-yr-old Chilean male diagnosed with primary aldosteronism (PA). All family members were also studied: his biological parents, 1 brother, 6 sisters, 2 daughters, and 1 son. Plasma renin activity, serum aldosterone, and its ratio were measured in all patients. Genetic analyses were performed using long-extension PCR (XL-PCR), DNA sequencing and Southern blot methods. Results: PA was diagnosed for the index case, 1 of his daughters, his son but not for his parents or siblings. XL-PCR and Southern blotting demonstrated the presence of the chimeric CYP11B1/CYP11B2 gene solely in PA-affected subjects, suggesting a case of a de novo mutation. Sequence analysis showed the unequal cross-over CYP11B1/CYP11B2 at intron 2 (c.2600-273 CYP11B2). We also identified a polymorphism at the same intron (c.2600-145C>A CYP11B2) in the genome of the index case's father. Conclusion: We describe an unprecedented case of unequal cross-over mutation for the chimeric CYP11B1/CYP11B2 gene causing FH-I, which may be linked to a polymorphism in the index case's father germ line.
AB - Familial hyperaldosteronism type I (FH-I) is an autosomal dominant disorder caused by an unequal cross-over of the gene encoding steroid 11βhydroxylase (CYP11B1) and aldosterone synthase (CYP11B2), giving rise to a chimeric CYP11B1/CYP11B2 gene that displays aldosterone synthase activity regulated by ACTH instead of angiotensin II. Aim: To report an unprecedented case of a de novo unequal cross-over mutation between CYP11B1 and CYP11B2 genes causing FH-I. Patients and methods: The index case is a 45-yr-old Chilean male diagnosed with primary aldosteronism (PA). All family members were also studied: his biological parents, 1 brother, 6 sisters, 2 daughters, and 1 son. Plasma renin activity, serum aldosterone, and its ratio were measured in all patients. Genetic analyses were performed using long-extension PCR (XL-PCR), DNA sequencing and Southern blot methods. Results: PA was diagnosed for the index case, 1 of his daughters, his son but not for his parents or siblings. XL-PCR and Southern blotting demonstrated the presence of the chimeric CYP11B1/CYP11B2 gene solely in PA-affected subjects, suggesting a case of a de novo mutation. Sequence analysis showed the unequal cross-over CYP11B1/CYP11B2 at intron 2 (c.2600-273 CYP11B2). We also identified a polymorphism at the same intron (c.2600-145C>A CYP11B2) in the genome of the index case's father. Conclusion: We describe an unprecedented case of unequal cross-over mutation for the chimeric CYP11B1/CYP11B2 gene causing FH-I, which may be linked to a polymorphism in the index case's father germ line.
KW - Chimeric CYP11B1/CYP11B2 gene
KW - Familial hyperaldosteronism type I
KW - Glucocorticoid-remediable aldosteronism
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U2 - 10.3275/7171
DO - 10.3275/7171
M3 - Article
C2 - 20634641
AN - SCOPUS:79956366912
SN - 0391-4097
VL - 34
SP - 140
EP - 144
JO - Journal of Endocrinological Investigation
JF - Journal of Endocrinological Investigation
IS - 2
ER -