Mark R. Gray

Congenital absence of the uterus and vagina is not commonly transmitted as a dominant genetic trait: Outcomes of surrogate pregnancies

OBJECTIVE To determine the inheritance pattern of congenital absence of the uterus and vagina in affected women undergoing surrogacy IVF with this disorder. DESIGN Retrospective study. SETTING A hospital-based reproductive endocrinology and infertility center. PATIENT(S) Women diagnosed with congenital absence of the uterus and vagina undergoing IVF with subsequent transfer of embryos to a surrogate uterus. INTERVENTION(S) Questionnaires were sent to all infertility treatment centers performing surrogate procedures. MAIN OUTCOME MEASURE(S) Number, gender, and frequency of congenital anomalies in progeny. RESULT(S) Thirty-two of 53 surveyed programs responded (60%). One hundred sixty-two IVF cycles were performed, and 34 liveborn children were delivered (half female). No congenital anomalies were found, except for one male child with a middle ear defect and hearing loss. CONCLUSION(S) These results strongly suggest that congenital absence of the uterus and vagina, if genetically transmitted, is not inherited commonly in a dominant fashion.

Further evidence that the WT1 gene does not have a role in the development of the derivatives of the müllerian duct

OBJECTIVE Several lines of evidence suggest that expression of the WT1 transcription factor gene is necessary for normal development of the renal and male reproductive systems. Female patients with severe reproductive tract developmental defects were examined for WT1 gene mutations. STUDY DESIGN The WT1 gene was analyzed in 25 patients with congenital absence of the uterus and vagina for mutations. Genomic deoxyribonucleic acid prepared from blood leukocytes was subjected to Southern blot analysis and denaturing gradient gel electrophoresis. RESULTS Common WT1 gene deoxyribonucleic acid sequence polymorphisms were found in both normal control subjects and patients with congenital absence of the uterus and vagina. No deoxyribonucleic sequence differences or mutations likely to cause congenital absence of the uterus and vagina were detected in the patients. CONCLUSIONS The absence of WT1 gene mutations in patients with congenital absence of the uterus and vagina supports the hypothesis that WT1 expression is required only for later urogenital development, after the mesonephric and paramesonephric ducts have already formed.

Role for anti-Müllerian hormone in congenital absence of the uterus and vagina.

Molecular genetic techniques were used to determine if mutations in the genes encoding anti-Müllerian hormone (AMH) (also known as Müllerian inhibiting substance (MIS)) and its receptor (AMHR) are commonly present in patients with congenital absence of the uterus and vagina (CAUV). Twenty-two CAUV patients and 96 control subjects from diverse ethnic groups were studied after obtaining informed consent. Genomic DNA samples prepared from leukocytes were digested separately with several different restriction enzymes, and the resultant fragments were analyzed for restriction fragment melting polymorphisms (RFMPs) by denaturing gradient gel electrophoresis (DGGE). Electrophoretic mobility of DNA fragments which were 200-700 base pairs in length was compared using polyacrylamide gels that included linear gradients of denaturing solvents designed to separate DNA fragments according to sequence-dependent variation in thermal stability. Two RFMPs were found in the AMH gene in both patients and normal control subjects. One RFMP in the AMHR gene was present at low frequencies in both patients and normal control subjects. No RFMPs specific to CAUV patients were found in either gene. Because no mutations or rare DNA sequence polymorphisms were detected in the AMH and the AMHR genes in this group of CAUV patients, it is unlikely that either gene commonly has an etiologic role in CAUV.

CCN5, a secreted protein, localizes to the nucleus.

CCN5, a member of the CCN family of growth factors, inhibits the proliferation and migration of smooth muscle cells in cell culture and animal models. Expressed in both embryonic and adult tissues, CCN5 exhibits a matricellular localization pattern characteristic of secreted proteins that are closely associated with the cell surface. In addition to this observed expression pattern, immunohistochemical evidence suggests the presence of nuclear CCN5 in some cells. To determine if CCN5 localizes to the nucleus we performed immunofluorescence, confocal imaging, and cell fractionation to corroborate the immunohistochemical observations. After confirming the presence of nuclear CCN5 using four independent experimental methods, we identified a single putative nuclear localization signal in the von Willebrand factor C domain of mouse and rat CCN5. Site directed mutagenesis of the three basic amino acids in the putative nuclear localization sequence did not prevent nuclear localization of CCN5 in four different cell types, suggesting that CCN5 nuclear transport is not mediated by the only canonical nuclear localization signal present in the primary amino acid sequence. Future work will address the mechanism of nuclear localization and the function of nuclear versus secreted CCN5.

CCN5 Expression in mammals. II. Adult rodent tissues.

CCN5 is a secreted heparin- and estrogen-regulated matricellular protein that inhibits vertebrate smooth muscle cell proliferation and motility. CCN5 is expressed throughout murine embryonic development in most organs and tissues. However, after embryonic development is complete, we hypothesized that CCN5 distribution would be largely restricted to small set of tissues, including smooth muscle cells of the arteries, uterus, airway, and digestive tract. Because CCN5 inhibits proliferation of smooth muscle cells in vitro, it might function to prevent excessive growth in vivo. In contrast, another member of the CCN family, CCN2, promotes smooth muscle cell proliferation in vitro, and thus it was expected that its expression levels would be low in uninjured normal adult tissues. Frozen sections from adult tissues and organs were analyzed immunohistochemically using anti-CCN5 and anti-CCN2 antibodies. Both proteins were detected in arteries, the uterus, bronchioles, and the digestive tract as expected, and also in many other tissues including the pancreas, spleen, liver, skeletal muscle, ovary, testis, thymus, brain, olfactory epithelium, and kidney. CCN5 and CCN2 protein was found in smooth muscle, endothelial cells, epithelial cells, skeletal muscle, cells of the nervous system, and numerous other cell types. In many cells, both CCN5 and CCN2 was present in the nucleus. Rather than having opposite patterns of localization, CCN5 and CCN2 often had similar sites of expression. The wide distribution of both CCN5 and CCN2 suggests that both proteins have additional biological functions beyond those previously identified in specific cellular and pathological models.

High-frequency DNA sequence polymorphisms in the insulin receptor gene detected by denaturing gradient gel blots

A limiting factor in the study of genetic determinants of human disorders is the availability of informative DNA markers. In this report, we describe an application of the denaturing gradient gel blot method for detecting high-frequency DNA sequence polymorphisms in the human insulin receptor locus. Using two restriction enzymes and cDNA probes for the insulin receptor, we found five DNA polymorphisms. The probe that contained exons 4-10 of the insulin receptor gene detected two two-allelic polymorphisms in HinfI digests, one at denaturant concentrations of 38%/39% and the other at 46%/48%. The probe that contained exons 14-22 detected three two-allelic polymorphisms in Sau96I digests, the first at denaturant concentrations of 34%/35%, the second at 38%/39%, and the third at 46%/47%. All these DNA polymorphisms segregated in families in a Mendelian fashion, and the allelic distribution for each of them did not deviate from Hardy-Weinberg equilibrium. The identified polymorphisms were in linkage equilibrium and provided sufficient genetic information to determine parental haplotypes at the insulin receptor locus in small two-generation families. The denaturing gradient gel blot method is a very sensitive technique for identifying sequence polymorphisms in genomic DNA; its application will facilitate the search for genes involved in the development of many inherited disorders.

Use of denaturing gradient gel blots to screen for point mutations in the factor VIII gene

Denaturing gradient gel electrophoresis (DGGE) is commonly used to search for point mutations in DNA fragments amplified in vitro by the polymerase chain reaction (PCR). For the complete detection of mutations in large genes with many exons, the DGGE‐PCR approach, or any other PCR‐based method, requires many primer sets and amplification reactions to scan the entire protein‐coding sequence. We previously demonstrated that DGGE analysis using DNA blots detects mutations in Drosophila genes and sequence polymorphisms in human genes without prior PCR amplification. To determine if human point mutations could be detected using denaturing gradient gels (DGG blots), genomic DNA samples from hemophilia A families were analyzed for mutations in the factor VIII (FVIII) gene. Restriction enzyme digested DNA samples were subjected to DGGE and transferred to nylon blots. Hybridization of the DGG blots with FVIII cDNA probes revealed mutant and polymorphic DNA sequence differences. Among 26 affected families that were not carriers of intron 22 inversion mutations, 18 family‐specific DNA fragment polymorphisms and one multiexon deletion were mapped. DNA sequencing of eight patient‐specific polymorphic DNA fragments revealed six single base change mutations, one 4 bp deletion, and one 13 bp duplication. Hum Mutat 12:393–402, 1998.

Rapid identification of deoxyribonucleic acid sequence differences in cytochrome P-450 21-hydroxylase (CYP21) genes with denaturing gradient gel blots

Denaturing gradient gel electrophoresis was used to identify single-base differences in the cytochrome P-450 21-hydroxylase (CYP21) genes of 132 unrelated control individuals and family members of three unrelated patients with 21-hydroxylase deficiency. The salt-wasting variety was caused by gene deletion and gene conversion/deletion mutations in affected members of two families studied. The simple virilizing form, present in the third family, was caused by an apparent point mutation not detectable by routine Southern blots. We have detected many restriction fragment melting polymorphisms in the CYP21 genes of the members of both salt-wasting families and normal individuals with denaturing gradient gel electrophoresis. We also identified a restriction fragment melting polymorphism specific for the simple virilizing patient in the third family. The data demonstrate that the CYP21 genes are highly polymorphic and that denaturing gradient gel electrophoresis is useful for genomic deoxyribonucleic acid analysis of patients with 21-hydroxylase deficiency.

Gonadotropin-releasing hormone-associated peptide gene sequences in women with hyperprolactinemia**Supported by the Dental Research Institute and the Department of Obstetrics and Gynecology, Medical College of Georgia, Augusta, Georgia.††Presented at the 39th Annual Meeting for the Society for Gynecologic Investigation, San Antonio, Texas, March 18 to 21, 1992.

OBJECTIVE To determine if mutations in the structural gene for gonadotropin-releasing hormone (GnRH)-associated peptide are present in women with hyperprolactinemia. DESIGN Patients with hyperprolactinemia and controls were studied retrospectively for GnRH-associated peptide gene mutations. SETTINGS Patients seen in a clinical setting were studied at a medical school laboratory setting. PATIENTS Fifteen women with hyperprolactinemia and two fertile controls with normal prolactin levels were studied. INTERVENTIONS Genomic deoxyribonucleic acid (DNA) was extracted from each patient and subjected to Southern blot analysis and polymerase chain reaction (PCR). For Southern blot analysis, DNA was digested with EcoRI, XbaI, BglII, PstI, and BamHI and hybridized to two DNA probes for GnRH-associated peptide. Exons II to IV, which encode for the structural gene, were amplified by PCR. MAIN OUTCOME MEASURES Fragment sizes from autoradiographs were compared among patients and controls. Amplified PCR products of exons II to IV of the GnRH-associated peptide were also compared. RESULTS No large deletions, insertions, or polymorphisms were identified in women with hyperprolactinemia or controls by Southern blotting. Each of the exons was present and of normal size by PCR in the study patients and controls. CONCLUSIONS No large deletions of the GnRH-associated peptide gene appear to be present in our patients with hyperprolactinemia. Small deletions, insertions, or point mutations are not excluded by this analysis.