POR polymorphisms are associated with 21 hydroxylase deficiency

Area of Science:

• Endocrinology
• Genetics
• Pediatric Endocrinology

Background:

• Congenital 21 hydroxylase deficiency (21-OHD) exhibits variable genotype-phenotype correlations.
• Modifier genes are hypothesized to influence 21-OHD clinical and hormonal variability.
• The P450 oxidoreductase (POR) gene is a potential candidate for modulating 21-OHD phenotypes.

Purpose of the Study:

• To investigate the association between POR gene polymorphisms and clinical features in patients with 21-OHD.
• To determine if POR gene variations contribute to the spectrum of 21-OHD, from classic to non-classic forms.
• To evaluate the impact of POR polymorphisms on the severity of classic 21-OHD.

Main Methods:

• Sequencing of the POR gene in 96 patients with 21-OHD (49 classic, 47 non-classic) and 43 controls.
• Analysis of POR gene polymorphisms, including rs2228104 and the rs2286822/rs2286823 haplotype.
• Statistical evaluation of allelic risk and confidence intervals for observed associations.

Main Results:

• The prevalence of POR polymorphisms was similar between 21-OHD patients and controls.
• The rs2228104 polymorphism was significantly associated with non-classic 21-OHD (allelic risk 7.09).
• The rs2286822/rs2286823 haplotype correlated with more severe classic 21-OHD phenotypes, including salt-wasting form, higher Prader stage, elevated ACTH, and earlier diagnosis.

Conclusions:

• POR gene polymorphisms play a role in the clinical presentation of 21-OHD.
• These polymorphisms influence predisposition to classic versus non-classic 21-OHD.
• POR gene variations are associated with the severity of classic adrenal hyperplasia in 21-OHD.