Cigdem Cinar

A genetic survey of 1935 Turkish men with severe male factor infertility

Male factor infertility is the sole reason in approximately 25% of couples who suffer from infertility. Genetic factors such as numerical and structural chromosomal abnormalities and microdeletions of the Y chromosome might be the cause of poor semen parameters. The results of karyotype analyses and Y-chromosome microdeletions of 1935 patients with severe male factor infertility, which is the largest series from Turkey, were assessed retrospectively. The frequency of cytogenetic abnormalities among 1214 patients with non-obstructive azoospermia (NOA) and 721 patients with severe oligoasthenoteratozoospermia (OAT) were 16.40 and 5.83% respectively. The overall incidence of Y-chromosome microdeletion was 7.70%. The incidence of Y chromosome microdeletion in patients with NOA and OAT was 9.51 and 1.86% respectively. The abnormality rate increased with the severity of infertility. Some patients (n = 22) were carriers of both chromosomal abnormalities and Y-chromosome microdeletions. Results suggest the need for genetic screening and proper genetic counselling before initiation of assisted reproduction treatment.

Genetic diagnosis in infertile men with numerical and constitutional sperm abnormalities.

Infertile men having numerical or structural sperm defects may carry several genetic abnormalities (karyotype abnormalities, Y chromosome microdeletions, cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations, androgen receptor gene mutations, and abnormalities seen in sperm cells) leading to this situation. First we aimed to investigate the relationship between the numerical and constitutional (morphological) sperm anomalies and the genetic disorders that can be seen in infertile males. Our other aim was to compare two different kinds of kits that we use for the detection of Y chromosome microdeletions. Sixty-three infertile males [44 nonobstructive azoospermic, 8 severe oligozoospermic, and 11 oligoasthenoteratozoospermic] were investigated in terms of somatic chromosomal constitutions and microdeletions of the Y chromosome. Sperm aneuploidy levels were analyzed by fluorescence in situ hybridization (FISH) in sperm cells obtained from the semen of six OAT patients. Microdeletion and sex chromosome aneuploidy (47,XXY) rates in somatic cells were found to be approximately 3.2% and 4.7%, respectively. Sperm aneuploidy rates were determined as 9%, 22%, and 47% in three patients out of six. Two of these three patients also had high rates of head anomalies in semen samples. High correlation was found between sperm aneuploidy rates and sperm head anomalies. Since the introduction of the assisted reproductive techniques for the treatment of severe male infertility, genetic tests and genetic counseling became very important due to the transmission of genetic abnormalities to the next generation. Thus in a very near future, for a comprehensive male infertility panel, it will be essential to include additional genetic tests, such as CFTR gene mutations, sperm mitochondrial DNA mutations, and androgen receptor gene mutations, besides the conventional chromosomal analyses, Y chromosome microdeletion detection, and sperm-FISH analyses.

Sperm fluorescence in situ hybridization analysis reveals normal sperm cells for 14;14 homologous male Robertsonian translocation carrier.

OBJECTIVE To report the presence of normal sperm cells for chromosome 14 in a homologous 14;14 Robertsonian translocation carrier. DESIGN Case report. SETTING In vitro fertilization clinic and genetics laboratory in a private hospital. PATIENT(S) Infertile couple referred for IVF. INTERVENTION(S) Conventional cytogenetic and fluorescence in situ hybridization (FISH) techniques were used in karyotype and sperm FISH analysis. Three IVF treatments were performed, two of which included preimplantation genetic diagnosis (PGD). MAIN OUTCOME MEASURE(S) Cytogenetic analysis revealed pure 45,XY,t(14;14)(q10;q10) karyotype. Sperm FISH analysis for chromosome 14 revealed 13% normal sperm cells in the sperm sample. RESULT(S) Sperm FISH analysis revealed 13% normal sperm cells for chromosome 14 in the homologous 14;14 Robertsonian translocation carrier. The couple underwent two IVF cycles together with PGD. In the first trial there was no suitable embryo for transfer. In the second trial one normal blastocyst was transferred on day 6. However, pregnancy was not established in this second PGD cycle. CONCLUSION(S) To our knowledge, this is the first sperm FISH study revealing the presence of normal sperm in the ejaculate of a pure homologous translocation carrier. The PGD study performed for this couple is also unique in the literature.

Preimplantation genetic diagnosis (PGD) for extremes—successful birth after PGD for a consanguineous couple carrying an identical balanced reciprocal translocation

OBJECTIVE To report a healthy birth after preimplantation genetic diagnosis (PGD) performed for a consanguineous couple carrying an identical familial reciprocal translocation in both partners. DESIGN Case report. SETTING In vitro fertilization (IVF) clinic and genetic laboratory in a private hospital. PATIENT(S) Consanguineous couple carrying the same balanced reciprocal translocation: 46,XX,t(1;16)(q12;q11.2) and 46,XY,t(1;16)(q12;q11.2). INTERVENTION(S) 25 oocyte-cumulus complexes were retrieved 36 hours after human chorionic gonadotropin injection; metaphase II oocytes were fertilized by intracytoplasmic sperm injection; single blastomere biopsy was performed on 15 embryos on day 3; one embryo was found to be normal or balanced according to fluorescent in situ hybridization studies, embryo transfer was performed on day 4. MAIN OUTCOME MEASURE(S) Healthy birth of homozygous double translocation carrier twins with 46,XY,t(1;16)(q12;q11.2)mat,t(1;16)(q12;q11.2)pat karyotype. RESULT(S) Healthy monozygotic male twins were born at 36 weeks of gestation. Karyotype studies of the babies revealed that they are double translocation homozygotes: 46,XY,t(1;16)(q12;q11.2)mat,t(1;16)(q12;q11.2)pat. They are healthy and more than 4 years old later show no physical or mental abnormalities. CONCLUSION(S) To our knowledge, this is the first PGD study performed for a couple who carry the same reciprocal translocation. The twins born after this study are rare examples in the literature of healthy balanced reciprocal translocation homozygotes.