The combination of genetic variants of the FSHB and FSHR genes affects serum FSH in women of reproductive age.

STUDY QUESTION: What is the effect of FSHB-211G>T together with the FSHR 2039 A>G on serum FSH in women? SUMMARY ANSWER: Serum FSH levels are affected by the combination of genetic polymorphisms in FSHR and FSHB. WHAT IS KNOWN ALREADY: The relationship between SNPs of the FSHR gene and serum FSH has not been completely clarified. Genetic variants of the FSHB gene have been associated with variation in gene transcription and serum FSH levels in men. No data have been published on the effect of the FSHB-211G>T in women, alone or in combination with the FSHR 2039 A>G. STUDY DESIGN, SIZE, DURATION: This study was a prospective study including 193 healthy women of reproductive age. PARTICIPANTS/MATERIALS, SETTING, METHODS: Infertile and otherwise healthy eumenorrheic women (n = 193) with normal BMI and serum FSH levels were recruited for the study. In all women early follicular phase FSH and AMH were measured by commercial assays, and antral follicle count was measured by transvaginal ultrasound. Genomic DNA was purified from total peripheral blood and genotyping for the two SNPs was performed. MAIN RESULTS AND THE ROLE OF CHANCE: No significant gradients of increasing or decreasing Day 3 FSH across the FSHR 2039 (AA/AG/GG) and FSHB-211 (GG/GT/TT) genotypes, respectively, were observed. When women were stratified according to the FSHR 2039, and FSHB-211 genotypes a statistically significant reduction of d3 FSH was shown in the group of women with the FSHB-211 GT + TT/FSHR2039 AA genotype compared with the FSHB-211 GG/FSHR2039 GG genotype, hence confirming a possible additive effect of the different SNPs in FSHR and FSHB on regulating serum FSH. LIMITATIONS, REASONS FOR CAUTION: This finding requires an independent confirmation. However, it confirms the relationship between serum FSH and FSHB together with FSHR gene polymorphisms already reported in males. WIDER IMPLICATIONS OF THE FINDINGS: The knowledge of the FSHB/FSHR genotype combination is fundamental for the proper interpretation of serum FSH levels in women of reproductive age. STUDY FUNDING/COMPETING INTERESTS: Merck Serono supported the study in the form of a research grant for the laboratory session. None of the authors have any competing interest to declare.

Role of Multidrug-Resistance Protein 2 in coproporphyrin transport: results from experimental studies in bile fistula rat models.

Coproporphyrin (CP) is one of the main by-products of heme biosynthesis and its abnormal accumulation is associated with different forms of porphyria. Indirect data obtained from animal and human models have suggested a possible role for Multidrug Resistance-associated Protein 2 (MRP2) and other MRPs in hepatocyte excretion of CP. Using normal, MRP2-deficient and a cholestatic rat model, we have assessed the role of MRPs in CP disposition. MRP levels were assayed using immunofluorescence. Biliary and urinary excretion patterns of CP and conjugate bilirubin were measured during equimolar infusions of CP isomers with and without phenoldibromopthalein sulfonate (BSP), a well-known MRP2 substrate. Our results suggest a role for the MRP system as a possible regulator of CP traffic and accumulation in normal and pathological conditions. Alteration in this systems (as observed in cholestatic disease) may play an important role in triggering clinical expression of porphyria in individuals with underlying mutations leading to porphyrin accumulation and may help explain the phenotypic heterogeneity in patients affected by different forms of porphyrias.

Clinical, biochemical and genetic characteristics of Variegate Porphyria in Italy.

Variegate Porphyria (VP) is an autosomal dominant disorder found worldwide but is rare in Italy. In this study we provide an overview of clinical, biochemical and genetic background of 33 Italian VP patients diagnosed in the last fifteen years. About 70% of patients had experienced clinical symptoms: 43.4% had photosensivity, 8.7% acute attacks and 47.8% both. Among the 33 patients, 14 different mutations were identified. Of these only 6 defects have been previously described in other countries and 8 are unique having been identified for the first time in Italy. Two of these, the c.851G>T and the c.1013C>G, were found in two and four unrelated families respectively. No mutation has been found in homozygosis and no significant correlation has been observed between specific clinical and biochemical manifestations and the type of mutation. In contrast, normal faecal protoporphyrin excretion was high predictive of silent phenotype. Normal urinary excretion of PBG and ALA, predicted absence of neurovisceral symptoms. This paper represents the first compilation of data on genotype-phenotype relation in Italian patients with VP.

Hyperhomocysteinaemia in HIV-infected patients: determinants of variability and correlations with predictors of cardiovascular disease.

OBJECTIVE: We evaluated hyperhomocysteinaemia (HHcy) in a cohort of HIV-infected patients in order to assess its relation to cardiovascular risk (CVR) and identify determinants of HHcy variability. METHODS: Cross-sectional observational study. HIV-infected patients on stable highly active antiretroviral therapy (ART) were evaluated for the presence of the metabolic syndrome, lipodystrophy and traditional CVR factors. Plasma homocysteine levels were measured using high-performance liquid chromatography. RESULTS: Five hundred and sixty-seven patients (38% female) with a median age of 44 years were included in the study. Homocysteine (Hcy) was significantly higher in patients with the metabolic syndrome and lipodystrophy. No significant association was found between Hcy levels and the use of ART. However, Hcy was associated with higher blood pressure, waist circumference and waist-to-hip ratio, total lean body mass, visceral adipose tissue (VAT), VAT/total adipose tissue, homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides, high-density lipoprotein cholesterol, apolipoprotein A1, B, and creatinine. All 10-year CVR assessment scores were significantly associated with Hcy. In a multivariate regression model, systolic blood pressure, vitamin supplementation and HOMA-IR were significantly and independently related to Hcy. CONCLUSIONS: Hcy is elevated in HIV-infected patients and is significantly associated with increased CVR. Measurement of Hcy might be useful in identifying particularly high-risk populations at whom therapeutic interventions could be targeted.

Co-existence of two functional mutations on the same allele of the human ferrochelatase gene in erythropoietic protoporphyria.

Erythropoietic protoporphyria (EPP) is an autosomal dominant disease with incomplete penetrance due to reduced activity of ferrochelatase (FECH), a mitochondrial enzyme that catalyzes the final step of the heme biosynthetic pathway. The clinical phenotype of EPP results from co-inheritance of a mutated allele and a wild-type low-expressed allele of the FECH gene. To date, more than 88 different mutations have been identified in the FECH gene of patients with EPP. There are evidences suggesting that an entire haplotype (-251G, IVS1-23T and IVS3-48C) reduces allele expression. In this study, we searched for the -251A/G, IVS1-23C/T and IVS3-48T/C polymorphisms in two unrelated Italian families with EPP. In all the patients, carrying the -250G>C mutation in the promoter region, the IVS3-48C on the other allele showed apparent homozygosity and absence of Mendelian segregation. By RNA and long polymerase chain reaction analysis, we identified a deletion of 5576 bp (g12490_18067), including exons 3 and 4, in cis with the -250G>C mutation in the promoter.