[Clinical phenotype and genetic analysis of a fetus with recombinant chromosome 8 syndrome].

OBJECTIVE: To explore the clinical characteristics and molecular genetic mechanism of a fetus with recombinant chromosome 8 (Rec8) syndrome. METHODS: A fetus who was diagnosed with Rec8 syndrome at the Provincial Hospital Affiliated to Shandong First Medical University on July 20, 2021 due to high risk for sex chromosomal aneuploidy indicated by non-invasive prenatal testing (NIPT) (at 21st gestational week) was selected as the study subject. Clinical data of the fetus was collected. G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out on the amniotic fluid sample. Peripheral blood samples of the couple were also subjected to G banded karyotyping analysis. RESULTS: Prenatal ultrasonography at 23rd gestational week revealed hypertelorism, thick lips, renal pelvis separation, intrahepatic echogenic foci, and ventricular septal defect. The karyotype of amniotic fluid was 46,XX,rec(8)(qter→q22.3::p23.1→qter), and CMA was arr[GRCh37]8p23.3p23.1(158049_6793322)×1, 8q22.3q24.3(101712402_146295771)×3. The karyotype of the pregnant woman was 46,XX,inv(8)(p23.1q22.3), whilst that of her husband was normal. CONCLUSION: The Rec8 syndrome in the fetus may be attributed to the pericentric inversion of chromosome 8 in its mother. Molecular testing revealed that the breakpoints of this Rec8 have differed from previously reported ones.

Microsatellite polymorphism in the fibrillin 3 gene and susceptibility to PCOS: a case-control study and meta-analysis.

The D19S884 marker at the fibrillin 3 gene has been analysed as a candidate location for polycystic ovary syndrome (PCOS) mainly in Caucasian descendants. A case-control study was performed with 272 PCOS women and 271 controls to test the hypothesis that variants in the D19S884 marker increase susceptibility to PCOS in Chinese women and a meta-analysis was undertaken to clarify whether there is an allele consistently contributing to the susceptibility. The association analysis showed that PCOS women were significantly different from controls in the distribution of D19S884 allele frequencies. Instead of the well-known A8 allele, the most common allele in Chinese population was proved to be A7, and the allele frequencies of A7 were statistically different between cases and controls (P=0.037). The meta-analysis of A8 and A7 only identified A8 as a significant allelic association at the D19S884 marker in all combined samples (A8: OR 1.391, 95% CI 1.169-1.654; A7: OR 1.154, 95% CI 0.894-1.490). In conclusion, the association study showed a potential association of the D19S884 marker with PCOS in Chinese Han women and the meta-analysis identified that A8 may increase susceptibility to PCOS. Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, and it affects an estimated 15% of women worldwide based on the Rotterdam criteria. Many studies in Caucasian descendants suggested that variants of the D19S884 marker at the fibrillin 3 gene are associated with the risk of this syndrome. Here we performed a case-control study with 272 PCOS women and 271 controls to investigate whether variants in the D19S884 marker increase susceptibility to PCOS in Chinese women. We also carried out a meta-analysis of some relevant studies to find a more reliable result. Our association analysis showed that PCOS women were significantly different from controls in the distribution of D19S884 allele frequencies, and instead of the well-known A8 (the letter 'A' represents 'allele'), the most common allele in Chinese population was proved to be A7, whose allele frequencies were statistically different between cases and controls. The meta-analysis of A8 and A7 only identified A8 as a significant allelic association at the D19S884 marker in all combined samples. In conclusion, our association study showed a potential association of the D19S884 marker with PCOS in Chinese Han women and the meta-analysis identified that A8 may increase susceptibility to PCOS.

Association between polymorphisms of the CYP11A1 gene and polycystic ovary syndrome in Chinese women.

The cholesterol side chain cleavage enzyme (CYP11A1) gene plays an important part in the synthesis of sex hormones and has been reported to be involved in the pathogenesis of polycystic ovary syndrome. A case-control study including 314 PCOS patients and 314 controls was conducted to assess the association of the SNPs rs4077582 and rs11632698 in CYP11A1 with PCOS using the polymerase chain reaction-restriction fragment length polymorphism method. Thereafter, 100 DNA samples were re-genotyped by direct sequencing for confirmation. The genotypic distribution of rs4077582 in women with PCOS differed from that in controls (P = 0.002). No such distributional difference was found in rs11632698 (P = 0.912). Data from our previous study of these two SNPs in another population including 290 PCOS patients and 344 controls was combined with the current data. Combined analysis (a total of 1262 participants, including 604 PCOS patients and 658 control women) showed a much more significant difference in the genotypic distribution of rs4077582 between PCOS and controls (P < 0.001). The T allele was more prevalent in PCOS patients (Odds ratio = 1.314; 95 % CI 1.122-1.540). The testosterone levels among the three genotypes for rs4077582 were different in the control group, as were the LH levels and the LH/FSH ratio. Therefore, SNP rs4077582 in CYP11A1 is strongly associated with susceptibility to PCOS and may alter the testosterone levels by the regulation of LH in different genotypes. No association was observed in rs11632698.

SNP rs2470152 in CYP19 is correlated to aromatase activity in Chinese polycystic ovary syndrome patients.

CYP19 encodes aromatase, a key enzyme essential for estrogen biosynthesis. Single nucleotide polymorphism (SNP) rs2470152 in CYP19 is associated with serum estradiol (E2) level and the E2/T (estradiol/testosterone) ratio. A case­control study including 661 individuals [364 polycystic ovary syndrome (PCOS) patients and 297 controls] was conducted to assess the association of SNP rs2470152 with PCOS. The subjects were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method. Hormone levels were analyzed among various genotypes. The genotypic distributions of rs2470152 did not differ in PCOS patients when compared to the controls. However, differences in the E2/T ratio were detected, exhibiting a lower ratio in the heterozygous TC genotype in PCOS patients (p=0.01036) and controls (p=0.000). Testosterone levels also differed between the three genotypes of PCOS patients (p=0.00625), with a higher level in the TC genotype. Therefore, rs2470152 in CYP19 was not a major etiological factor for PCOS; however, the heterozygous TC genotype may inhibit aromatase activity, resulting in hyperandrogenism, particularly in PCOS patients.

Polymorphisms of the HSD17B6 and HSD17B5 genes in Chinese women with polycystic ovary syndrome.

OBJECTIVES: To investigate the polymorphisms of the 17ß-hydroxysteroid dehydrogenase type 5 and type 6 (HSD17B5 and HSD17B6) genes in Chinese women with polycystic ovary syndrome (PCOS). METHODS: Two hundred twenty-two PCOS patients and 283 controls were studied. Menarche age was recorded. Body mass indices (BMI) were calculated. Blood samples were obtained for single nucleotide polymorphism (SNP) analyses and hormone measurements. Genotyping of HSD17B6 and HSD17B5 in cases and controls was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: The SNP rs898611 of the HSD17B6 gene (TT, CT, CC) in women with PCOS (0.680, 0.270, 0.050, respectively) did not differ from those in controls (0.700, 0.258, 0.042, respectively), and the SNP rs3763676 of the HSD17B5 gene (AA, AG, GG) was rare in Chinese women. Total testosterone and other reproductive hormones, such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), LH/FSH, and estradiol (E(2)), were also similar among the different genotypes of the HSD17B6 in the PCOS subjects and the controls, whereas BMI was different in the three genotypes of the HSD17B6 in PCOS subjects. CONCLUSIONS: Our data suggest that there is no association of HSD17B6 and HSD17B5 variants with the occurrence of PCOS in the Chinese population, but the polymorphism of SNP rs898611 is associated with BMI in PCOS patients.