The P20R mutation of αB-crystallin diminishes its anti-apoptotic activity in human lens epithelial cells.

αB-crystallin acts as an anti-apoptosis protein in human lens epithelial (HLE) cells. We recently identified a missense mutation in αB-crystallin that changes proline 20 to an arginine (P20R) in a Chinese family with autosomal dominant congenital posterior polar cataract. The impact of the P20R mutation on the anti-apoptosis function remains unclear. To explore the anti-apoptotic activity of αB-crystallin wild type (αB-wt) and its P20R mutant under oxidative stress, HLE cells were transfected with αB-wt and αB-P20R constructs and expression was measured by western blotting. Flow cytometry and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP digoxigenin nick end-labelling (TUNEL) staining were performed to investigate apoptosis. We found that αB-wt performed a dominant role in inhibiting stress-induced apoptosis, but this function was impeded in cells expressing αB-P20R. The P20R mutant of αB-crystallin exhibits diminished anti-apoptotic activity compared with the native protein.

A duplication upstream of SOX9 was not positively correlated with the SRY­negative 46,XX testicular disorder of sex development: A case report and literature review.

The 46,XX male disorder of sex development (DSD) is rarely observed in humans. Patients with DSD are all male with testicular tissue differentiation. The mechanism of sex determination and differentiation remains to be elucidated. In the present case report, an 46,XX inv (9) infertile male negative for the sex­determining region of the Y chromosome (SRY) gene was examined. This infertile male was systemically assessed by semen analysis, serum hormone testing and gonadal biopsy. Formalin­fixed and paraffin­embedded gonad tissues were assessed histochemically. The SRY gene was analyzed by fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR). The other 23 specific loci, including the azoospermia factor region on the Y chromosome and the sequence-targeted sites of the SRY­box 9 (SOX9) gene were analyzed by PCR. The genes RSPO1, DAX1, SOX3, ROCK, DMRT1, SPRY2 and FGF9 were also assessed using sequencing analysis. Affymetrix Cytogenetics Whole Genome 2.7 M Arrays were used for detecting the genomic DNA from the patient and the parents. The patient with the 46,XX inv (9) (p11q13) karyotype exhibited male primary, however, not secondary sexual characteristics. However, the patient's mother with the 46, XX inv (9) karyotype was unaffected. The testicular tissue dysplasia of the patient was confirmed by tissue biopsy and absence of the SRY gene, and the other 23 loci on the Y chromosome were confirmed by FISH and/or PCR. The RSPO1, DAX1, SOX3, ROCK, DMRT1, SPRY2 and FGF9 genes were sequenced and no mutations were detected. A duplication on the 3 M site in the upstream region of SOX9 was identified in the patient as well as in the mother. The patient with the 46,XX testicular DSD and SRY­negative status was found to be infertile. The duplication on the 3 M site in the upstream region of SOX9 was a polymorphism, which indicated that the change was not a cause of 46,XX male SDS. These clinical, molecular and cytogenetic findings suggested that other unidentified genetic or environmental factors are significant in the regulation of SDS.

46,XX testicular disorder of sexual development with SRY-negative caused by some unidentified mechanisms: a case report and review of the literature.

BACKGROUND: 46,XX testicular disorder of sex development is a rare genetic syndrome, characterized by a complete or partial mismatch between genetic sex and phenotypic sex, which results in infertility because of the absence of the azoospermia factor region in the long arm of Y chromosome. CASE PRESENTATION: We report a case of a 14-year-old male with microorchidism and mild bilateral gynecomastia who referred to our hospital because of abnormal gender characteristics. The patient was treated for congenital scrotal type hypospadias at the age of 4 years. Semen analysis indicated azoospermia by centrifugation of ejaculate. Levels of follicle-stimulating hormone and luteinizing hormone were elevated, while that of testosterone was low and those of estradiol and prolactin were normal. The results of gonadal biopsy showed hyalinization of the seminiferous tubules, but there was no evidence of spermatogenic cells. Karyotype analysis of the patient confirmed 46,XX karyotype and fluorescent in situ hybridization analysis of the sex-determining region Y (SRY) gene was negative. Molecular analysis revealed that the SRY gene and the AZFa, AZFb and AZFc regions were absent. No mutation was detected in the coding region and exon/intron boundaries of the RSPO1, DAX1, SOX9, SOX3, SOX10, ROCK1, and DMRT genes, and no copy number variation in the whole genome sequence was found. CONCLUSION: This study adds a new case of SRY-negative 46,XX testicular disorder of sex development and further verifies the view that the absence of major regions from the Y chromosome leads to an incomplete masculine phenotype, abnormal hormone levels and infertility. To date, the mechanisms for induction of testicular tissue in 46,XX SRY-negative patients remain unknown, although other genetic or environmental factors play a significant role in the regulation of sex determination and differentiation.

Polymorphisms in estrogen receptors predict the risk of male infertility: a meta-analysis.

BACKGROUND: Estrogen receptors play an important role in mediating estrogen action on target tissues, and the estrogen is relevant to male infertility. Single nucleotide polymorphisms (SNPs) in estrogen receptors may be associated with the risk of male infertility. A variety of case control studies have been published evaluating this association. However, the accumulated studies have shown inconsistent conclusions. METHODS: To further determine the potential association between the four common SNPs (rs2234693, rs9340799, rs1256049 and rs4986938) in estrogen receptors gene and male infertility, this meta-analysis was performed according to the 10 published case control studies. The odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the strength of the associations. RESULTS: It was revealed that the sub-group analysis by the ethnicity, for the rs2234693, a significant association in the comparison of CC vs. TT (OR = 0.61, 95% CI: 0.40-0.93), CT vs. TT (OR = 0.67, 95% CI: 0.49-0.93) and CC + CT vs. TT (OR = 0.66, 95% CI: 0.49-0.89) in the Asian population with male infertility. For rs9340799 polymorphism, increased risks were observed for the comparison of AA vs. GG (OR = 1.75, 95% CI: 1.15-2.68) and AA vs. GA + GG (OR = 1.38, 95% CI: 1.02-1.88). For rs1256049 polymorphism, the comparison of the GA vs. GG (OR = 1.52, 95% CI: 1.00-2.31) and AA + GA vs. GG (OR = 1.74, 95% CI: 1.03-2.94), also increased risks present in Asian and Caucasian population, respectively. CONCLUSIONS: The rs2234693C allele was associated with the decreased risk for male infertility; however, the rs9340799AA genotype and the rs1256049GA genotype were associated with an increased risk for male infertility.

Meiotic prophase I defects in an oligospermic man with Wolf-Hirschhorn syndrome with ring chromosome 4.

BACKGROUND: Ring chromosomes are often associated with spermatogenetic failure. However, the mechanism is poorly understood. We here reported a single man with severe oligospermia and a ring chromosome 4 with a microdeletion at 4p16.3. RESULTS: Synapsis (as SCP3), recombination (as MLH1) and transcriptional inactivation (as BRCA1) in a testicular biopsy were examined by fluorescence immunostaining. In the oligospermia patient, 35.4% of spermatocytes were in zygotene phase compared with 5.2% in controls. The patient had a significantly reduced recombination frequency with mean of 45.9 MLH1 foci/cell compared with 47.8 in controls. In the patient, chromosome 4 in all pachytene cells displayed loop formation with varying degrees of unpaired regions. BRCA1 localized along asynapsed regions regardless of XY body association. CONCLUSIONS: Ring chromosome 4 might affect the progression of meiosis I prophase, synapse formation, and transcriptional activation of asynapsed areas, and impair male fertility.

The effect of induced anti-follicle-stimulating hormone autoantibody on serum hormone level and apoptosis in rat testis.

AIMS: Anti-follicle-stimulating hormone (FSH) autoantibody was found to highly correlate with oligospermia and asthenospermia, but the actual effect of FSH autoantibody on spermatogenesis is still unknown. MAIN METHODS: In this study, 21-day rats were immunized seven times with FSH peptides linked with Keyhole Limpet Hemocyanin (KLH) (experimental group) or KLH (control group) every 2 weeks. Luteinizing hormone (LH) and inhibin B level in the immunized rat sera were measured by enzyme-linked immunosorbent assay (ELISA). Apoptosis of spermatogenic cells in the testis was detected by in situ end labeling method (TUNEL), and the mRNAs of Bax, Bcl-2 and Caspase-3 in testis were detected by fluorescent Quantitative PCR. KEY FINDINGS: Compared with the control, serum inhibin B level was significantly decreased at all time points (34.49%, 23.20%, and 37.00%) (p<0.05). There was no difference in the serum LH level between experimental and control groups. FSH peptide immunization increased the apoptosis of spermatogenic cells in the testis that was associated with an imbalance of Bax and Bcl-2 expression and upregulation of Caspase-3. SIGNIFICANCE: These results suggest that FSH autoantibody could cause the reduction of inhibin B, thereby inducing hypospermatogenesis via augment of spermatogenic cell apoptosis.

[Cigarette smoking affects sperm plasma membrane integrity].

OBJECTIVE: To detect sperm plasma membrane integrity (PMI) of cigarette smoking infertile males using SYBR-14/ PI fluorescent staining and flow cytometry and investigate its clinical significance. METHODS: We collected semen samples from 132 cigarette smoking infertile men and 70 normal fertile controls, the former divided into a heavy-smoker group (> 20 cigarettes a day, n = 68) and a light-smoker group (< or = 20 cigarettes a day, n = 64). We performed computer-assisted semen analysis of the semen samples, and determined sperm PMI by flow cytometry after rinsing with PBS and staining by SYBR-14/PI, the sperm with normal PMI indicated as the percentage of those emitting green fluorescence (SYBR-14+/PI- %), dead sperm as the percentage of those emitting red (SYBR-14-/PI+), and moribund sperm as the percentage of those emitting both green and red (SYBR-14+/PI+). RESULTS: Both the heavy- and light-smoker groups showed significant differences in SYBR-14-/PI+ % and SYBR-14+/PI- % from the normal controls (P < 0.01 or P < 0.05). SYBR-14+/PI- % was remarkably lower, while SYBR-14-/PI+ % markedly higher in the heavy-smoker than in the light-smoker group (P < 0.05). There was a significant correlation between SYBR-14+/PI- % and sperm motility (r = 0.938, P = 0.000). CONCLUSION: SYBR-14/PI fluorescent staining and flow cytometry analysis could quickly and exactly detect sperm PMI. Cigarette smoking reduces sperm PMI and consequently sperm motility, which might be an important factor of male infertility.

Gonadotropin-releasing hormone positively regulates steroidogenesis via extracellular signal-regulated kinase in rat Leydig cells.

Gonadotropin-releasing hormone (GnRH) is secreted from neurons within the hypothalamus and is necessary for reproductive function in all vertebrates. GnRH is also found in organs outside of the brain and plays an important role in Leydig cell steroidogenesis in the testis. However, the signalling pathways mediating this function remain largely unknown. In this study, we investigated whether components of the mitogen-activated protein kinase (MAPK) pathways are involved in GnRH agonist (GnRHa)-induced testis steroidogenesis in rat Leydig cells. Primary cultures of rat Leydig cells were established. The expression of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and the production of testosterone in response to GnRHa were examined at different doses and for different durations by RT-PCR, Western blot analysis and radioimmunoassay (RIA). The effects of GnRHa on ERK1/2, JNK and p38 kinase activation were also investigated in the presence or absence of the MAPK inhibitor PD-98059 by Western blot analysis. GnRHa induced testosterone production and upregulated 3ß-HSD expression at both the mRNA and protein levels; it also activated ERK1/2, but not JNK and p38 kinase. Although the maximum effects of GnRHa were observed at a concentration of 100 nmnol L⁻¹ after 24 h, activation of ERK1/2 by GnRHa reached peak at 5 min and it returned to the basal level within 60 min. PD-98059 completely blocked the activation of ERK1/2, the upregulation of 3ß-HSD and testosterone production. Our data show that GnRH positively regulates steroidogenesis via ERK signalling in rat Leydig cells. ERK1/2 activation by GnRH may be responsible for the induction of 3ß-HSD gene expression and enzyme production, which may ultimately modulate steroidogenesis in rat Leydig cells.

Association between ubiquitin-specific protease USP26 polymorphism and male infertility in Chinese men.

BACKGROUND: Increased sperm ubiquitin was inversely associated with sperm count and motility. Ubiquitin-specific protease 26 (USP26), which is an X-linked gene, has been studied as a potential infertility gene. There are conflicting reports on whether variations in USP26 are associated with spermatogenesis. METHODS: In order to assess that USP26 polymorphisms contribute to male infertility, we screened 221 infertile men with azoospermia, oligozoospermia, asthenozoospermia, or oligoasthenozoospermia, and 101 control fertile men using DNA sequencing. RESULTS: There were six polymorphisms identified, including an unreported variation (508G>A, G170R). Only the allele frequency of 576G>A was significantly higher in fertile men than infertile patients (p<0.001), although this variant does not result in an amino acid change. The major haplotypes in fertile and infertile men were TGATC (76.2% vs 47.5% of the population, p<0.001) and TGGTC (14.9% vs 39.4%, p<0.001). The haplotype TGATC was under-transmitted, whereas the haplotype TGGTC was over-transmitted in infertile men with asthenozoospermia and oligoasthenozoospermia. CONCLUSIONS: Our results indicated the variation of USP26 was not directly associated with human sperm count but suggested it might be a potential role in sperm motility. The 576G>A synonymous single nucleotide polymorphism (SNP) might have a role in improving the sperm motility.

[Mutation analysis of NF2 gene and clinical investigation in a Chinese family with neurofibromatosis type II].

OBJECTIVE: To report a heterozygous RNA-splicing mutation (IVS3+ 3A to C) of NF2 gene in a Chinese family with autosomal dominant neurofibromatosis type II and investigate the relationship between the genotype and phenotype. METHODS: The proband with bilateral vestibular schwannomas underwent gamma knife radiosurgery two years earlier. DNA of blood samples from all affected individuals, suspected individuals and unaffected relatives of the family was extracted and amplified to detect the polymorphisms at loci D22S1150 and D22S268 that are linked with the NF2 gene. Two-point LOD score was calculated. The promoter region, 17 exons and exon/intron boundaries of NF2 gene were amplified and sequenced for the proband. The exon 3/intron 3 boundaries of NF2 gene was amplified and sequenced for the other 3 patients, 1 suspected individual, 9 unaffected members of the family and 150 unrelated controls. RESULTS: The result of two-point linkage analysis suggested that NF2 gene was a candidate gene (Zmax= 2.109, θ = 0.00, locus D22S1150). DNA sequencing revealed a heterozygous splicing mutation in intron 3 (IVS3+ 3A to C) for the proband. Identical mutation was also observed in the other 3 patients and 1 suspected individual. No mutation was found in the 9 normal family members and 150 unrelated controls, which was consistent with the clinical diagnosis. CONCLUSION: This is the first report of familial neurofibromatosis type II with a splicing mutation of IVS3+ 3A to C of the NF2 gene. The mutation might be responsible for the neurofibromatosis type II in the family.

[Mutation of the USP26 gene in spermatogenesis dysfunction].

The ubiquitin specific protease 26 (USP26) gene is located at Xq26.2 and present as a single exon on the X chromosome encoding for a protein of 913 amino acids. It belongs to a large family of deubiquitinating enzymes, and is exclusively expressed in the testis. There are conflicting reports on whether mutations in USP26 are associated with male infertility. This article updates the researches on the USP26 gene, its complicated relationship with male spermatogenesis dysfunction, the role of its mutation in male infertility, its geographical or ethnic distribution, and its evolution.

A novel insertion mutation in the SEDL gene results in X-linked spondyloepiphyseal dysplasia tarda in a large Chinese pedigree.

BACKGROUND: Spondyloepiphyseal dysplasia tarda (SEDT) is an X-chromosome linked primary skeletal dysplasia characterized by a disproportionate short-trunked short stature, dysplasia of the large joints and flattened thoracic and lumber vertebral bodies. The objective of this study is to describe a large Chinese SEDT family with a milder phenotype and describe the molecular and clinical findings. METHODS: Eight affected males of the family were diagnosed with SEDT according to their clinical and radiological features. Direct DNA sequencing of the SEDL gene was performed. RT-PCR experiments on total RNA from blood lymphocytes were performed to confirm the defect on the SEDL gene. A short summary of all currently known SEDL gene mutations is presented. RESULTS: DNA sequencing revealed that all the affected males carried an insertion mutation (c.370-371insA) unreported previously, predicted to result in frameshifts and generate a premature stop codon (p.S124fsX127). The identical mutation was also observed in a 10-year old presymptomatic boy of the family. Eight female carriers had the typical sequencing chromatograms of heterozygotes. CONCLUSIONS: Identification of the novel insertion mutation (c.370-371insA) in this SEDT family enables carrier detection and presymptomatic/prenatal diagnosis, but also the detailed molecular and clinical features will be useful for extending the evidence for genetic and phenotypic heterogeneity in SEDT.

Rapid molecular prenatal diagnosis of spondyloepiphyseal dysplasia congenita by PCR-SSP assay.

Heterozygous mutations of COL2A1 gene are responsible for type II collagenopathies. The common skeletal phenotypes include achondrogenesis type II, hypochondrogenesis, Stickler dysplasia, Kniest dysplasia, late onset spondyloepiphyseal dysplasia, and spondyloepiphyseal dysplasia congenita (SEDC). Prevention of SEDC can be achieved by prenatal diagnosis. This study reports the first rapid molecular prenatal diagnosis of SEDC performed in China by polymerase chain reaction sequence-specific primer (PCR-SSP) analysis. The pregnant woman we previously reported with SEDC carried the G to A substitution at nucleotide 1510 in exon 23 of COL2A1 gene, which caused a change from glycine to serine at codon 504 (G504S). By the time the woman got pregnant again, she had terminated two pregnancies and still had no child. In the first pregnancy, the molecular mutation of the family was not yet identified, and therefore prenatal diagnosis was unable to be performed by DNA analysis. In the second pregnancy, G504S mutation was found from fetal DNA. At the time of her third pregnancy, the woman and her husband became extremely worried about the potential SEDC for the fetus. For this reason, a quick and reliable molecular prenatal diagnosis of SEDC was performed by a PCR-SSP on an amniocyte sample collected at the 14th week of pregnancy. No mutation of the fetal DNA was identified. The result was obtained within 24 h after the sample was collected. The technique could be applied in confirmatory diagnosis and prenatal diagnosis for the affected family.

[Observation of spermatogenic cells for infertile patients with Y-chromosomal microdeletion].

OBJECTIVE: To assess the spermatogenic function of the infertile patients with Y-chromosomal microdeletion. METHODS: Thirty-five 23-44 years old patients with microdeletions of Y chromosome were included in this study. Three semen analyses confirmed that 26 cases were non-obstructive azoospermia and 9 oligospermia with sperm count < 1 x 10(6)/ml. They were divided into 3 groups by the locus of deletion, 5 cases of AZFa + b + c deletion in group 1, 4 cases of AZFb + c and 3 cases of AZFb deletion in group 2, and 23 cases of AZFc deletion in group 3. Semen was collected and centrifuged, the supernatant removed and the centrifugate applied on the clean slides after dilution. Following Wright's-Giemsa staining, the slides were viewed under the microscope. Testis histopathological biopsy was performed for 6 of the cases. RESULTS: In group 1, no spermatogenic cells were observed but only Sertoli cells in 1 case, with a consistency between the result of spermatogenic cell test and that of testis biopsy. In group 2, spermatogenic cell tests revealed spermatocytes in 6 cases, 2 were proved by testis biopsy with sperm maturation arrest in the primary spermatocyte stage, and spermatogenic cells of all developmental stages were seen in 1 AZFb deletion patient with the same sperm maturation arrest as the above two. In group 3, only primary spermatocytes were detected by spermatogenic cell test in 5 oligospermia patients but no spermatogenic cells in the 15 azoospermia cases, and biopsy revealed 2 cases of Sertoli cell-only syndrome. CONCLUSION: The spermatogenic cell test can effectively assess the spermatogenic function of AZF deletion patients. Non-invasive and easily accepted by patients, it is highly recommendable for the evaluation of spermatogenesis of patients with Y-chromosomal microdeletion.

[Genetic causes of male infertility].

The causes of spermatogenetic failure found in most cases of non-ohstmctive azoospermia or severe oligospermia remain largely unclear. It is estimated that in about 30% of the cases, male infertility is due to genetic causes, including chromosomal abnormalities, Y chromosome microdeletions, gene mutations, etc. Klinefelter's syndrome and microdeletions in the Y chromosome long arm (Yq) represent the most frequent molecular genetic cause of severe infertility. Gene mutations involved in male infertility include the cystic fibrosis transmembrane conductance regulator (CFTR) gene, androgen receptor (AR) gene, insulin-like factor 3 (INSL3) gene and leucine-rich repeat-containing G-protein coupled receptor 8 (LGR8) gene. CFTR mutations cause cystic fibrosis, absence of vas deferens and non-obstructive azoospermia. The AR gene mutations are responsible for the androgen insensitivity syndrome and spermatogenetic damage. And INSL3 and LGR8 gene mutations have been associated with abnormalities in testis descent and cryptorchidism. Meta-analyses have revealed a significant association between the polymorphism and male infertility only for partial AZFc deletion, CAG repeat length in the AR gene and methylenetetrahydrofolate reductase (MTHFR) gene. This paper mainly reviews the genetic causes of male infertility and the genetic polymorphisms possibly associated with male infertility.

Long-term effects of phytoestrogen daidzein on penile cavernosal structures in adult rats.

OBJECTIVES: Daidzein is a soy isoflavone with estrogenic activity present in plant-based food items and health foods and used as an alternative therapy for cancer and cardiovascular diseases. The present study was designed to investigate the effects of daidzein on the cavernosal components, including smooth muscle cells, collagen fibers, and elastic fibers, that are the key structures fundamental for erection. METHODS: A total of 30 adult male Sprague-Dawley rats were equally divided into a normal control group, three experimental groups, and one positive control group. The three experimental groups were given daidzein at a dose of 2, 20, and 100 mg/kg body weight daily, and the positive control group received 0.1 mg diethylstilbestrol per animal daily for 90 days. The collagen fibers and elastic fibers in the corpora cavernosa were measured using histochemical or immunohistochemical techniques, and their relative contents were evaluated quantitatively or semiquantitatively. RESULTS: The relative content of collagen fibers in the corpus cavernosa in rats treated with low-dose daidzein (2 mg/kg) was not significantly different from that of controls, as was the case for the smooth muscle and elastic fiber content (all P >0.05). However, the relative content of the collagen fibers was significantly increased in rats treated with a medium dose (20 mg/kg) and a high dose (100 mg/kg) of daidzein. The smooth muscle cell and elastic fiber content was reduced significantly compared with that of the controls (all P <0.01). Similar alterations were observed in the diethylstilbestrol-treated rats. CONCLUSIONS: These results suggest that daidzein, if ingested in a relatively large amount, could induce histopathologic alterations in the penile cavernosal structures characterized by an increase in the collagen content and a reduction in smooth muscle cell and elastic fiber content, which might be suggestive of erectile dysfunction.

Exposure of juvenile rats to the phytoestrogen daidzein impairs erectile function in a dose-related manner in adulthood.

Health benefits of isoflavones such as genistein and daidzein have led to an increasing interest in consuming soybeans or soy-containing food. However, possible adverse effects of such plant estrogens on the male reproductive system, particularly penile erection, have not been sufficiently evaluated. In previous research, we observed that exposure of adult rats to daidzein could attenuate apomorphine-induced erections. To identify the impact of daidzein exposure in early life on erectile function, we evaluated erectile capacity using an apomorphine-induced erectile test and determining intracavernous pressure after exposure of juvenile rats to daidzein at a dose of 2, 20, or 100 mg/kg for 90 days. Meanwhile, the levels of sex hormones, including testosterone, luteinizing hormone, and follicle-stimulating hormone, were determined. Both subtypes of the estrogen receptor (alpha and beta) in the corpora cavernosa were also detected immunohistochemically. When the rats were examined at adulthood, we observed that those animals treated with a medium (20 mg/kg) or high (100 mg/kg) dose of daidzein, but not with a low dose (2 mg/kg), showed lower plasma testosterone levels and attenuated erectile parameters, including apomorphine-induced erections and intracavernous pressure concomitant with markedly decreased expression of estrogen receptor beta in the corpora cavernosa. However, the penis still grew to its normal size, as in controls. Thus, these results suggested that exposure of juvenile rats to daidzein in a relatively large amount could adversely affect penile erection in adulthood.

Molecular prenatal diagnosis in 2 pregnancies at risk for spondyloepiphyseal dysplasia congenita.

BACKGROUND: Spondyloepiphyseal dysplasia congenita (SEDC) is an autosomal dominant skeletal dysplasia characterized by short stature, abnormal epiphyses, and flattened vertebral bodies. Secondary prevention of SEDC can be achieved by prenatal diagnosis. Reports of antenatally-diagnosed SEDC fetuses have been very rare and molecular prenatal diagnosis even rarer. We previously reported a familial G504S mutation in the type II collagen (COL2A1) gene resulting in SEDC. In this study, molecular prenatal diagnosis was performed to 2 couples in this family with pregnancies at risk for SEDC. METHODS: Amniotic fluid was sampled by amniocentesis under ultrasound guidance at 19+3 and 18+6 weeks' gestation, respectively. Karyotype and molecular genetic analysis were performed on cultured amniotic fluid cells. Maternal cell contamination was excluded by short tandem repeat (STR) analysis. Direct DNA sequencing and DHPLC were conducted to detect the potential mutation in exon 23 of COL2A1 gene. Both women underwent serial sonograms because they insisted that the molecular diagnosis should be confirmed by another method, although they had been informed that mutation analysis is predictive of the disease. RESULTS: Karyotype of both fetuses was normal and molecular genetic analysis revealed that fetus 1 carried a G504S mutation in exon 23, while fetus 2 was normal. In case 1, femur length of the fetus was markedly below the 5th centile at 23 weeks' gestation, which confirms the accuracy of molecular diagnosis. A medical termination was carried out at 27+5 weeks' gestation and a male fetus with a relatively large head and short limbs was delivered. The fetal radiograph demonstrated a number of features, including generalised platyspondyly, absent ossification of the vertebral bodies in the cervical region and significant shortening of the long bones. The diagnosis of SEDC was thus confirmed clinically. Ultrasound monitoring of fetus 2 showed that its femur length was normal for gestational age at repeated scans, which was consistent with the molecular diagnosis. CONCLUSIONS: Molecular analysis allows early and accurate prenatal diagnosis for SEDC once mutation is known in a family. However, considering the poor genotype/phenotype correlation in many cases of SEDC, the combination of ultrasound as well as molecular genetic approach might be needed.