46,XY phenotypic male with focal segmental glomerulosclerosis caused by the WT1 splice site mutation

OBJECTIVE: Frasier syndrome is characterized by progressive glomerulopathy due to nonspecific focal and segmental glomerulosclerosis (FSGS), 46,XY sex reversal and the development of gonadoblastoma from dysgenetic gonads. Donor splice site heterozygous mutations in intron 9 of the Wilms' tumor gene (WT1) cause this disease. We investigated whether WT1 mutations showed clinical heterogeneity. PATIENTS AND METHODS: A 6-year-old phenotypic boy was diagnosed as having FSGS. His karyotype was 46,XY. Gonadotropin-releasing hormone and human chorionic gonadotropin stimulation tests revealed normal luteinizing hormone, follicle-stimulating hormone and testosterone responses. The other patient was a 7-year-old 46,XY female with FSGS. Prophylactic gonadectomy was performed and gonadoblastoma was found. By polymerase chain reaction and direct sequencing, WT1 was analyzed in these patients. RESULTS AND CONCLUSION: Both patients had IVS9 + 5G-->A in intron 9 of the WT1. Our study indicates a normal 46,XY phenotypic male patient with FSGS. The phenotypic variations of the WT1 splice site mutations are further expanded.     

Molecular analysis of chromosome region 11p13 in patients with Drash syndrome

Summary The association of nephropathy, Wilms' tumour and genital abnormalities is known as Drash syndrome. Two of these features are also seen in the WAGR (Wilms' tumour, aniridia, genito-urinary abnormalities, mental retardation) complex, known to be associated with deletions of chromosome region 11p1S. We have carried out karyotypic and molecular studies in 10 Drash patients, 5 males and 5 females. All the males had a 46XY karyotype as did 3/5 of the phenotypic females, the other two having a 46XX karyotype. One of the 46XX females also had a deletion of region 11p13–p12, the only detectable autosomal chromosome abnormality in any of the patients studied. Lymphoblastoid cell lines were prepared from 6 of the Drash patients and were used in dosage studies using a variety of DNA probes from the 11p13 region. There was no evidence of microdeletions in any patient with a normal karyotype. Because of the 46XY karyotype in phenotypic females, selected X and Y chromosome loci were analysed and all found to be normal. Although Drash syndrome is likely to be of genetic origin, there are no readily detected deletions within the 11p13 region.     

Lymphocyte chromosome survey in 42 patients with retinoblastoma: Effort to detect 13q14 deletion mosaicism

Summary The results of a lymphocyte chromosome survey of retinoblastoma (Rb) patients using a method able to detect a relatively low proportion mosaicism of 13q14 deletion are presented. Three out of 42 Rb patients had abnormal karyotypes; two mosaic cases with the karyotype 46,XY,del(13) (q14.1q14.3)/46,XY and 46,XX,del(13)(q14.1q14.3)/46,XX(the proportions of 13q14-cells, 51% and 9%, respectively), and the other with the karyotype 46,XY,del(13)(q14.1q21.2). All of these three cases had bilateral sporadic Rb. Two mosaic cases had an apparently normal phenotype except for Rb. These data suggest that the frequency of Rb cases with a 13q- cell line in lymphocytes may be greater than that which has been reported.     

Syndrome de klinefelter et conseil génétique

Klinefelter’s syndrome is a common sex chromosomal aberration generally characterized by hypergonadotrophic hypogonadism and azoospermia. However, spermatogenesis impairment is variable and severe oligozoospermia can be found in some men, particularly those exhibiting a mosaic karyotype 47,XXY/ 46,XY. New reproductive technologies, such as intracytoplasmic sperm injection (ICSI), allow Klinefelter patients to have a progeny, even those who are azoospermic after testicular sperm recovery. The question therefore arises of whether or not there is a genetic risk for pregnancies from affected fathers. Sperm karyotyping, by in vitro penetration of zona-free hamster eggs or by fluorescence in-situ hybridization (FISH), is a method of choice for measuring aneuploidy rate in spermatozoa of patients carrying gonosomal abnormalities. A theoretical model would predict a high level of 24,XX and/or 24,XY disomic sperm cells in Klinefelter patients if 47,XXY spermatogonia were able to complete meiosis and achieve spermatogenesis. Interestingly, current observations show that the rate of abnormal spermatozoa in these patients is low, around 1–2%, which indicates that only 46,XY spermatogonia can produce mature sperm cells and that oligozoospermic Klinefelter patients probably carry a 47,XXY / 46,XY mosaicism, at least at the testicular level. However, this low but statistically significant level of disomic spermatozoa emphasizes the fact that their spermatogenesis occurs in a compromised environment which could increase the risk of meiotic errors. Therefore, the possible occurrence of autosomal aneuploidies in children born from Klinefelter fathers leads to the following recommendations: a) individual analysis by FISH of the sperm aneuploidy rate in each Klinefelter patient candidate for ICSI; b) proposal of fetal karyotyping after amniocentesis in pregnancies obtained by this technique.     

Isochromosome for the long arm of the Y in an infertile male

Summary A 37-year-old man investigated for infertility had bilateral atrophic testes. Cytogenetic investigations revealed a chromosome complement of 45,XO/46,Xi(Yq)/46,XY. Mechanisms for the origin of the i(Yq) are considered, and the relation of his chromosome constitution to his infertility and hypogonadism are discussed.     

The phenotype in partial 13q trisomies,apropos of a familial (13;15)(q22;q26) translocation

Summary A 12 month-old male patient with a karyotype 46, XY,-15,+der(15),t(13;15)(q22;q26)pat is presented. His stillborn sib showed malformations compatible with the 13q deletion syndrome, probably due to a 46,XY, der(13) karyotype. Phenotypic analysis of 41 cases from the literature with partial distal 13q (D13q) trisomies indicate that the segment 13q22 qter in trisomy with or without another concomitant aneusomy is sufficient to produce the majority of the trisomy 13 syndrome features, some of which (cleft palate, increased HbF and projections in PMN) are present in different non-overlapping partial 13q trisomies. About 82% of the D13q trisomies are inherited, more frequently from the mother.     

Etiologies of late puberty.

An expected lack of pubertal development can be due to an already diagnosed disease. The diagnosis of an unexpected lack of puberty is a difficult task. We have analyzed the etiologies of late puberty in 106 adolescents: 68 boys aged over 15 years and 38 phenotypic girls aged over 13 years. According to their clinical and biological (gonadotropin) data, they were classified in 3 groups. In the first group, hypergonadotropism was observed only in 19 females; pure gonadal dysgenesis was found in 2 cases with 46,XY, in 2 with 46,Xdel(Xq) karyotypes and 9 cases were 46,XX constitutions; 2 sisters had also blepharophimosis; in 3 cases the ovarian failure was due to autoimmune disease, and 1 case, genetically male, had 17 alpha-hydroxylase deficiency. The second group had gonadotropin insufficiency and consisted of 68 adolescents, 57 males and 11 females, with low gonadotropin levels: 33 were anosmic; in the boys, cryptorchism was present in 68% and micropenis in 31%; 38 had a familial history of hypogonadism, the transmission of which was matrilineal in 16, patrilineal in 13 and recessive autosomal in 7. The third group had low or low-normal gonadotropin levels: 22 cases of constitutional delay of puberty (11 cases in both sexes), demonstrated by further normal puberty during the follow-up. No clinical marker and familial history in 50% were noted.     

New cytogenetic variant of Orbeli's syndrome (46,XY/45,XY,-D/46,XY,Dq+)

Summary A newborn child with multiple congenital abnormalities, including severe hypoplastic thumb and atresia recti, is described. The cytogenetic analysis revealed a mosaicism 46,XY/45,XY,-D/46,XY,Dq+. The combination of mosaic D-monosomy and two cardinal features of 13q-syndrome give the possibility to consider this case as new cytogenetical variant of the Orbeli's syndrome.

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Zusammenfassung Ein Neugeborenes mit multiplen kongenitalen Abnormitäten einschließ-lich erheblicher Hypoplasie der Daumen und Atresia recti wird beschrieben. Die cytogenetische Analyse ergab ein Mosaik 46,XY/45,XY,-D/46,XY,Dq+ Die Kombination von Mosaik D-Monosomie und den zwei Hauptsymptomen des 13q-Syndroms läßt in diesem Falle eine neue cytogenetische Variante des Orbeli-Syndroms vermuten.

     

An infertile male with balanced Y;19 translocation. Review of Y;autosome translocations.

Cytogenetic studies on a phenotypically normal male, presenting with infertility, revealed a balanced Y;19 translocation - 46,XY,t (Y;19) (q11; p or q13). The patient had a normal hormone profile, but semen analysis showed immature cells in the fluid. The possible mechanisms causing the infertility are discussed. An extensive review of the literature of Y ; autosome translocations indicates that there are 2 types, those in which the broken segment of the Y is translocated to the short arm or centromeric region of an acrocentric chromosome, and those in which the Y material is translocated onto a long or short arm region of a non-acrocentric chromosome. The first type is less frequently associated with infertility and hypogonadism than the second type. There is presumptive evidence that the first type is non-random.     

Sotos syndrome with a balanced reciprocal translocation t(2;12)(q33.3;q15)

A balanced reciprocal translocation, 46,XY, t(2;12), was detected in a male infant who had the characteristic features of Sotos syndrome. His father's karyotype was normal, but his mother and an older brother had the same chromosomal abnormality without a history or clinical features of Sotos syndrome.     

Chromosome duplications and deletions and their mechanisms of origin.

Duplications and deletions of the same gene loci or chromosome regions are known to produce different clinical manifestations and are significant factors in human morbidity and mortality. Extensive cytogenetic and molecular cytogenetic studies with cosmid and YAC probes in two patients with unique mosaicism for reciprocal duplication-deletion allowed us to further understand the origin of these abnormalities. The first patient's mosaic karyotype was 46,XX, inv dup(11) (q23q13)/46,XX,del(11)(q13q23). The second patient had a 46,XY,dup(7)(p11.2p13)/46,XY,del(7)(p11.2p13)/46,XY karyotype. Fluorescence in situ hybridization studies on the first patient placed the two breakpoints near the folate-sensitive fragile sites FRA11A and FRA11B. The presence of repeated sequences responsible for these fragile sites may have been involved in the patient's duplication-deletion. Our investigation leads us to conclude that, in addition to known mechanisms (such as unequal crossovers between homologs, unequal sister chromatid exchanges, excision of intrachromatid loops, and meiotic recombination within a single chromatid), duplication-deletion can also arise by the formation of an overlying loop followed by an uneven crossover at the level of the DNA strand.     

AZF microdeletions on the Y chromosome of infertile men from Turkey

Intervals V and VI of Yq11.23 regions contain responsible genes for spermatogenesis, and are named as "azoospermia factor locus" (AZF). Deletions in these genes are thought to be pathogenetically involved in some cases of male infertility associated with azoospermia or oligozoospermia. The aim of this study was to establish the prevalence of microdeletions on the Y chromosome in infertile Turkish males with azoospermia or oligozoospermia. We applied multiplex polymerase chain reaction (PCR) using several sequence-tagged site (STS) primer sets, in order to determine Y chromosome microdeletions. In this study, 61 infertile males were enrolled for the molecular AZF screening program. In this cohort, one infertile male had 46,XX karyotype and the remaining had 46,XY karyotypes. Forty-eight patients had a diagnosis of azoospermia and 13 had oligozoospermia. Microdeletions in AZFa, AZFb and AZFc (DAZ gene) regions were detected in two of the 60 (3.3%) idiopathic infertile males with normal karyotypes and a SRY translocation was determined on 46,XX male. Our findings suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments.     

Paternal reciprocal translocation t(11;16)(p13;q24.3) in a Silver-Russel syndrome patient

We describe a 7-month-old male child with Silver-Russel syndrome (SRS) phenotype, presented with two major clinical features: low birth weight, short stature, and minor features, such as macrocephaly, clinodactyly, essential for the diagnosis of SRS. Routine cytogenetic studies with GTG-banding showed 46,XY,t(11;16)(p13;q24.3). Fluorescence in situ hybridisation (FISH) with single copy probes BAC (11p13) and PAC (16q24.3), showed a reciprocal translocation. Chromosomal analysis of the mother was normal and the phenotypically normal father had apparently identical translocation t(11;16)(p13;q24.3). The disruption of growth factor genes at 11p and 16q breakpoint regions due to reciprocal translocation in the father might have caused SRS phenotype in the child.     

Pericentric inversions of chromosome number 9: benign or harmful?

Pericentric inversions of chromosome number 9 have been studied in 4 different probands: a normal female with designation 46,XX,inv(9)(p12q13); a male with Down syndrome designated as 47,XY,+21,inv(9))p13q13); a premature infant with multiple, congenital malformations who was 46,XX,inv(9)(p12q21), and a Down syndrome proband with 47,XYqs,+21,inv(9)(p13q21). All 4 cases were shown to be inherited based on family studies. These families are discussed with reference to the literature as to what possible effect this structural change could have on the reproductive capability of a normal carrier and what guidelines are available for counseling such a carrier.     

Fetomaternal transfusion of blood lymphocytes and identification of the sex of the fetus

Karyotypes of blood lymphocytes were studied in 21 pregnant women. In 8 cases, 46,XY cells were found in the maternal blood and a boy was born in all cases. In 3 cases various chromosome rearrangements were seen. In 6 cases, no 46,XY cells were seen and a girl was born in each case. In 3 cases no 46,XY cell was observed (in 800 cells) and boys were born. In 3 other cases, a 46,XY cell was found and girls were born; all mothers had previously given birth to boys. In 1 case, 2 46,XY cells were observed, and a girl was born; the mother had had an induced abortion in the 3rd month of pregnancy 3 years earlier. It was concluded that the detection of a male fetus seems possible in pregnant women who have no previous male progeny. The persistence of cells from previous pregnancies appears to be a possibility, however.     

Placental alkaline phosphatase types in Germany

Summary Two children with autosomal deletion (46,XY,del(12)(p11) and 46,XY/46,XY, del(5)(p13)) and normal phenotype were found among 5049 consecutive newborn children. The mother of the proband with deletion short arm 5 had the karyotype 46,XX,9qh+, but the parents had otherwise normal chromosome constitution.

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Zusammenfassung Zwei Kinder mit autosomaler Deletion (46,XY,del(12)(p11) und 46,XY/46,XY,del(5)(p13)) bei normalem Phänotyp wurden unter 5049 auslesefrei gewonnenen Neugeborenen entdeckt. Die Mutter des Probanden mit der Deletion am kurzen Arm von Nr. 5 hatte den Karyotyp 46,XX,9qh+; sonst hatten die Eltern normale Chromosomen.

     

Prenatal diagnosis and molecular cytogenetic characterization of mosaic ring chromosome 13

We present prenatal diagnosis and molecular cytogenetic characterization of de novo mosaic r(13). A 32-year-old woman underwent amniocentesis at 18 weeks of gestation because of maternal anxiety. Amniocentesis revealed a karyotype of 46,XY,r(13)[33]/45,XY,-13[19]. aCGH on uncultured amniocytes at repeated amniocentesis detected a 4.22-Mb deletion at 13q34. Interphase FISH on 100 uncultured amniocytes showed the ratio of r(13):-13:idic r(13) as 85%:13%:2%. The cord blood had a karyotype of 46,XY,r(13)[91]/46,XY,idic r(13)[6]/45,XY,-13[3]. The placenta had a karyotype of 46,XY,mar(13)[31]/45,XY,-13[3]. Metaphase FISH confirmed that the marker chromosomes in placenta were derived from chromosome 13. aCGH on cultured placental cells detected a 77.81-Mb deletion at 13q13.3–q34. The fetus postnatally manifested facial dysmorphism. Prenatal diagnosis of r(13) should alert mosaicism for deletion/duplication of r(13) and distal 13q deletion. Fetoplacental chromosomal discrepancy of r(13) may exist in case of mosaic r(13) detected by amniocentesis.     

Microphthalmia with linear skin defects syndrome (MLS): a male with a mosaic paracentric inversion of Xp

The microphthalmia with linear skin defects syndrome (MLS) is an X-linked dominant disorder with male lethality. In the majority of the patients reported, the MLS syndrome is caused by segmental monosomy of the Xp22.3 region. To date, five male patients with MLS and 46,XX karyotype ("XX males") have been described. Here we report on the first male case with MLS and an XY complement. The patient showed agenesis of the corpus callosum, histiocytoid cardiomyopathy, and lactic acidosis but no microphthalmia, and carried a mosaic subtle inversion of the short arm of the X chromosome in 15% of his peripheral blood lymphocytes, 46,Y,inv(X)(p22.13 approximately 22.2p22.32 approximately 22.33)[49]/46,XY[271]. By fluorescence IN SITU hybridization (FISH), we showed that YAC 225H10 spans the breakpoint in Xp22.3. End-sequencing and database analysis revealed a YAC insert of at least 416 kb containing the genes HCCS and AMELX, and exons 2-16 of ARHGAP6. Molecular cytogenetic data suggest that the Xp22.3 inversion breakpoint is located in intron 1 of ARHGAP6, the gene encoding the Rho GTPase activating protein 6. Future molecular studies in karyotypically normal female MLS patients to detect submicroscopic rearrangements including the ARHGAP6 gene as well as mutation screening of ARHGAP6 in patients with no obvious chromosomal rearrangements will clarify the role of this gene in MLS syndrome.     

Partial androgen receptor deficiency and mixed gonadal dysgenesis in Drash syndrome

Summary Drash syndrome associates a nephropathy characterized by a diffuse mesangial sclerosis of early onset, Wilms tumor, and male pseudohermaphroditism (MPH). A patient with Drash syndrome is reported with the following: karyotype 46,XY, external genitalia near normal female, mixed gonadal dysgenesis, severe androgen receptor deficiency demonstrated for the first time in this syndrome. The possibility of a common genetic denominator with the del 11p13 WAGR complex is suggested. MPH/nephroblastoma association is common. Androgen receptor deficiency has been observed in one case of each syndrome, respectively.