Genetic analysis of a case with 11β hydroxylase deficiency caused by CYP11B2/CYP11B1 chimeric gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze a child with 11β hydroxylase deficiency (11β-OHD) due to CYP11B2/CYP11B1 chimeric gene.@*METHODS@#Clinical data of the child who was admitted to Henan Children's Hospital on August 24, 2020 were retrospectively analyzed. Peripheral blood samples of the child and his parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. RT-PCR and Long-PCR were carried out to verify the presence of chimeric gene.@*RESULTS@#The patient, a 5-year-old male, had featured premature development of secondary sex characteristics and accelerated growth, and was diagnosed with 21 hydroxylase deficiency (21-OHD). WES revealed that he has harbored a heterozygous c.1385T>C (p.L462P) variant of the CYP11B1 gene, in addition to a 37.02 kb deletion on 8q24.3. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.1385T>C (p.L462P) was rated as a likely pathogenic variant (PM2_Supporting+PP3_Moderate+PM3+PP4). The results of RT-PCR and Long-PCR suggested that CYP11B1 and CYP11B2 genes have recombined to form a CYP11B2 exon 1~7/CYP11B1 exon 7~9 chimeric gene. The patient was diagnosed as 11β-OHD and effectively treated with hydrocortisone and triptorelin. A healthy fetus was delivered following genetic counseling and prenatal diagnosis.@*CONCLUSION@#11β-OHD may be misdiagnosed as 21-OHD due to the potential CYP11B2/CYP11B1 chimeric gene, which will require multiple methods for the detection.

Clinical and genetic analysis of an infant with aldosterone synthase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical characteristics and genetic variants in a two-month-and-one-day male infant with aldosterone synthase deficiency.@*METHODS@#Clinical data of the child was collected. Whole exome sequencing was carried out by next generation sequencing(NGS). Candidate variants were verified by Sanger sequencing.@*RESULTS@#The infant had measured 54 cm (-2.1 SD) in length and 3.9 kg (-2.8 SD) in weight, and featured recurrent vomiting, poor feeding, apathetic appearance and failure to thrive. Blood electrolyte testing showed low sodium and increased potassium. Serum cortisol, adrenocorticotrophic hormone, 17-alpha-hydroxyl progesterone, androstenedione, and testosterone were all within the normal ranges. The plasma renin activity activity was increased, and plasma aldosterone level was low. NGS revealed that the infant has harbored compound heterozygous variants of the CYP11B2 gene, namely c.1334T>G(p.Phe445Cys) inherited from his father and c.1121G>A(p.Arg374Gln) inherited from his mother. Neither variant was reported previously, and both were predicted to be deleterious for the function of the protein product.@*CONCLUSION@#The compound heterozygous variants of c.1334T>G (p.Phe445Cys) and c.1121G>A (p.Arg374Gln) of the CYP11B2 gene probably underlay the disease in this patient.

Disruption of reproductive development in male rat offspring following gestational and lactational exposure to di-(2-ethylhexyl) phthalate and genistein

Studies of developmental effects of mixtures of endocrine disrupters on the male reproductive system are of great concern. In this study, the reproductive effects of the co-administration of di-2-(ethylhexyl) phthalate (DEHP) and genistein (GEN) during pregnancy and lactation were studied in male rat offspring. Pregnant Sprague-Dawley rats were gavaged from gestation day 3 to postnatal day 21 with vehicle control, DEHP 250 mg/kg body weight (bwyday, GEN 50 mg/kg bwday, GEN 400 mg/kg bwday, and two combinations of the two compounds (DEHP 250 mg/kg bwday + GEN 50 mg/kg bwday, DEHP 250 mg/kg bwday + GEN 400 mg/kg bwday). The outcomes studied were general morphometry (weight, AGD), testicular histology, testosterone levels, and expression at the mRNA level of genes involved in steroidogenesis. Organ coefficient, AGD / body weight1/3 י, serum testosterone concentration and genes involved in steroidogenic pathway expression when exposed to DEHP (250mg/kg bwday), GEN(50mg/kg bwday) or GEN(400mg/kg bwday) alone were not significantly different from the control group. When exposed to (DEHP 250mg/kg bwday +GEN 50mg/kg bwday) together during pregnancy and lactation, serum testosterone concentration, epididymis coefficient and Cypal17a1,Scarb1 m RNA expression significantly decreased compared to the control and GEN(50mg/kg bwday). When exposed to (DEHP 250mg/kg bwday +GEN 400mg/kg bwday) together during pregnancy and lactation, AGD / body weight1/3 י, serum testosterone concentration, testis and epididymis coefficient and Star, Cypal17a1 mRNA expression appeared significantly decreased compared to the control and DEHP/GEN single exposure, together with developmental impairment of seminiferous tubules and seminiferous epithelium. Overall, co-administration of DEHP and GEN during gestation and lactation seem to acts in a cumulative manner to induce the most significant alterations in the neonate, especially with GEN at high dose, although the effect of the DEHP-GEN mixture on adult offspring should be observed further.

Association of aldosterone synthase (CYP11B2 C-344T) gene polymorphism & susceptibility to essential hypertension in a south Indian Tamil population.

Background & objective: Renin-angiotensin aldosterone system (RAAS) plays an important role in the regulation of blood pressure. Aldosterone, synthesized by aldosterone synthase in the adrenal cortex is encoded by the CYP11B2 gene. In this case-control study we examined the association between CYP11B2 C-344T polymorphism and essential hypertension in south Indian Tamil population. Methods: The study was conducted in 406 hypertensive cases and 424 healthy controls from Tamil population. Genotyping was performed by PCR-restriction fragment length polymorphism method. Statistical analysis was performed by logistic regression analysis. Results: The 344TT homozygous variant genotype (OR-1.8; 95% CI: 1.1-2.8; P=0.02) and T allele (P=0.007) were found to be significantly associated with hypertension. In gender based analysis, the risk was significantly higher in male hypertensives (OR-1.8; 95% CI: 1.0-3.6, P=0.05) but not in female subjects. Interpretation & conclusion: A significant association between CYP11B2 gene polymorphism and essential hypertension was observed and the risk was confined to male subjects in south Indian Tamil population.

Genetic Analyses of the Chimeric CYP11B1/CYP11B2 Gene in a Korean Family with Glucocorticoid-Remediable Aldosteronism

Glucocorticoid-remediable aldosteronism (GRA) is an autosomal-dominant inheritable form of hyperaldosteronism with early onset hypertension. GRA is caused by unequal crossing-over of the steroid 11beta-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes. As a result of chimeric gene duplication, aldosterone is ectopically synthesized in the adrenal zona fasciculata under the control of adrenocorticotropin. Here, we describe three cases of GRA in a Korean family. The proband-a 21-yr-old female-was incidentally found to have high blood pressure (170/108 mmHg). Her 46-yr-old father had been treated twice for cerebral hemorrhage at the ages of 29 and 39 yr. Her 15-yr-old brother had a 2-yr history of hypertension; however, he was never treated. Their laboratory test results showed normokalemia, hyporeninemia, hyperaldosteronism, and a high plasma aldosterone concentration-to-plasma renin activity ratio. Normal saline loading failed to suppress aldosterone secretion. However, dexamethasone administration effectively suppressed their plasma aldosterone concentrations. Following genetic analyses with PCR and direct sequencing to document the chimeric gene and crossover site, respectively, we identified CYP11B1/CYP11B2 and determined the breakpoint of unequal crossover to be located between intron 2 of CYP11B1 and exon 3 of CYP11B2.

Marcadores de inflamación endotelial subclínica en una familia con hiperaldosteronismo familiar tipo I por mutación de novo / Subclinical endothelial inflammation markers in a family with type I familial hyperaldosteronism caused by a de novo mutation

Background: Type I familial hyperaldosteronism is caused by the presence of a chimaetic gene CYPl 1B1/CYP11BZ which encodes an enzyme with aldosterone synthetase activityregulated by adrenocorticotrophic hormone (ACTH). Therefore, in patients with FH I is possible to normalize the aldosterone levels with glucocorticoid treatment. Recently it has been shown that aldosterone plays a role in the production of endothelial oxidative stress and subclinical inflammation. Aim: To evaluate subclinical endothelial inflammation markers, Me Metalloproteinase 9 (MMP-9) and ultrasensitive C reactive protein (usPCR), before and after glucocorticoid treatment in family members with FH-I caused by a de novo mutation. Patients and methods: We report three subjects with FH-I in a single family (proband, father and sister). We confirmed the presence of a chimaeric CYPl 1B1/CYP11B2 gene by ¡ong-PCR in all of them. Paternal grandparents were unaffected by the mutation. The proband was a 13year-old boy with hypertension stage 2 (in agree to The JointNational Committee VII, JNC-vIl), with an aldosterone/plasma rennin activity ratio equal to 161. A DNA paternity test confirmed the parental relationship between the grandparents and father with the index case. MMP-9 and usPCR levels were determined by gelatin zymography and nephelometry, respectively. Results: All affected subjects had approximately a 50 percent increase in MMP-9 levels. Only the father had an elevated usPCR. The endothelial inflammation markers returned to normal range after glucocorticoid treatment. Conclusions: We report a family canying a FH-I caused by a de novo mutation. The elevation of endothelial inflammation markers in these patients and its normalization after glucocorticoid treatment provides new insight about the possible deleterious effect of aldosterone on the endothelium.

Variabilidad fenotípica y estrés oxidativo endotelial en una familia con hiperaldosteronismo familiar tipo I / Phenotypical variability and endothelial oxidative stress in a family with type I familial hyperaldosteronism

Type I familial hyperaldosteronism (HAF-I) is caused by the presence of a chimeric gene CYP11B1/CYP11B2 which encodes an enzyme with aldosterone synthetase activity regulated by ACTH. HAF-I patients present with severe hypertension at young ages and a greater risk of stroke. AIM: To characterize clinical and biochemical presentation of family members with HAF-I. To evaluate endothelial oxidative stress markers before and after glucocorticoid treatment. PATIENTS AND METHODS: We evaluated three family members with HAF-I confirmed with a genetic test (XL-PCR) for chimeric gene CYP11B1/CYP11B2. The index case was a 13 years old boy with stage 2 hypertension (Joint National Committee VIIth report), plasma aldosterone/ plasma renin activity (AP/ARP) ratio of161 and normal plasma potassium. His father had primary hyperaldosteronism diagnosed at 25 years of age with hypertension and hypokalemia. His sister was 15 years old, with a normal blood pressure and an AP/ARP ratio of 37.6. RESULTS: All subjects had plasma xanthine-oxidase levels in the upperlimit of normal. Malondialdehyde was above normal in the index case and his father. These markers returned to normal with glucocorticoid treatment. CONCLUSIONS: We report a HAF-I carrying family with a wide phenotypical variability between affected members. Elevation of endothelial oxidativestress markers and its normalization after glucocorticoid treatment, may indicate that aldosterone produces endothelial damage and increases cardiovascular risk.

Renin-Angiotensin-Aldosterone System (RAAS) Gene Polymorphism as a Risk Factor of Coronary In-Stent Restenosis

Intimal proliferation is a main cause of in-stent restenosis. Over-excretion of angiotensin I converting enzyme (ACE) and aldosterone is reported to stimulate intimal hyperplasia and the genetic effect of these molecules may alter the process of in-stent restenosis. We hypothesized that the genetic polymorphisms that alter the expression of genes such as ACE I/D, CYP11B2-344C/T, and AGT M235T can affect in-stent restenosis. We analyzed the angiographic and clinical data of 238 patients (272 stents) who underwent coronary stenting and follow-up angiography, and analyzed the genotypes of ACE I/D, CYP11B2-344T/C, and AGT M235T. There was no significant difference in age, sex, or lipid profiles between the patent and restenosis groups. Diabetes mellitus was more frequent in the binary restenosis group. Quantitative computer-assisted angiographic (QCA) analysis revealed that the risk of in-stent restenosis increased with lesion length and was inversely proportional to post- stenting minimal luminal diameter (MLD) and reference diameter. There was no difference in the frequency of binary restenosis between genotypes in each of the three genes. However, follow-up MLD was significantly smaller in the ACE DD genotype than in the ACE II or ID genotypes. Defining restenosis as MLD 2 mm, the restenosis rate was significantly higher in the ACE DD genotype than in the ACE II or ID genotypes. There was no significant synergistic effect between the three gene polymorphisms. In conclusion, while the ACE I/D polymor phism promoted the progress of in-stent restenosis and was of clinical significance, the other potential variables examined did not correlate with in-stent restenosis.

Alteraciones en la enzimología de la producción de aldosterona / Alterations in the enzymology of aldosterone production

El último paso para la producción de aldosterona (11-desoxicorticosterona a aldosterona) en mitocondrias de zona glomerulosa de adrenal de rata es catalizado por la enzima CYP11B2. CYP11B1, en zona fasciculata, transforma 11-desoxicorticosterona en corticosterona o 18-hidroxi-11-desoxicorticosterona. CYO11B1 y CYP11B2 tienen alta homología y sus genes se hallan en tándem en el cromosoma 8q22. Mutaciones en el gen de CYP11B2 y recombinaciones genéticas entre éste y el gen de CYP11B1 serían las responsables de las alteraciones en la enzimología de la producción de aldosterona, dando una nueva denominación y explicación a las deficiencias anteriormente conocidas como de CMOI y CMOII