Subfertile couple with inv(2),inv(9) and 16qh+

This case report presents two chromosomal inversions in one of partners from a subfertile couple. The woman was referred due to a spontaneous abortion in the 5th week of pregnancy. Cytogenetic examination showed that the proband's karyotype was normal: 46,XX,16qh+, as centromeric heterochromatin is thought to be clinically insignificant. However, the proband's partner occurred to be a carrier of two pericentric inversions. His karyotype was 46,XY,inv(2)(p11q13),inv(9)(p11q13). The abnormal karyotype is recognised as a possible reason of fertility problems in the investigated couple. The risk of further miscarriages is considered high, but the risk of progeny with abnormal karyotypes is rather low, as small inversions may lead to lethal recombinants.     

Molecular cytogenetic characterization of a familial balanced reciprocal translocation t(11;18) (q13.3; q23) associated with pregnancy wastage

A new male patient associated with a pregnancy wastage was detected in China. Cytogenetic analyses including G-banding, chromosome painting and observation of synaptonemal complexes (SCs) demonstrated that the pregnancy wastage was associated with a balanced reciprocal translocation t(11;18) (q13.3; q23). The proband was the carrier of the translocation and his karyotype was 46,XY,t(11;18)(11pter-->11q13.3:: 18q23-->18qter; 18pter-->18q23::11q13.3-->11qter). The pedigree was analyzed based on a G-banded karyotype of the nine familial members. The translocation chromosomes came from the proband's mother. The result of the SC observation in the proband showed that each of the spermatocytes displayed one quadrivalent during their pachytene stages. In the quadrivalents, there existed homologous and nonhomologous synapses and the latter occurred widely during early, middle and late pachytene stages. The reasons and genetic basis of the pregnancy wastage are discussed.     

Precocious puberty associated with partial trisomy 18q and monosomy 11q

We report a 10-years-old female patient with a partial trisomy 18q and monosomy 11q due to a maternal translocation. The phenotype of our proband is partially common with Jacobsen syndrome and duplication 18q but she has also some atypical anomalies such as precocious puberty, a retinal albinism and hypermetropia. Based on cytogenetics and FISH analysis, the karyotype of the proband was 46,XX,der(11)t(11;18)(q24;q13). To the best of our knowledge, this is the first report of precocious puberty associated with either dup(18q) or del(11q) syndromes.     

46,XX, der(15),t(Y;15)(q12;p11) karyotype in an azoospermic male

We report on a Yq/15p translocation in a 23-year-old infertile male referred for Klinefelter Syndrome testing, who had azoospermia and bilateral small testes. Hormonal studies revealed hypergonadotropic hypogonadism. Conventional cytogenetic procedures giemsa trypsin giemsa (GTG) and high resolution banding (HRB) and molecular cytogenetic techniques Fluorescence In Situ Hybridization (FISH) performed on high-resolution lymphocyte chromosomes revealed the karyotype 46,XX, t(Y;15)(q12;p11). SRY-gene was confirmed to be present by classical Polymerase Chain Reaction (PCR) methods. His father carried de novo derivative chromosome 15 [45,X, t(Y;15)(q12;p11)] and was fertile; the karyotype of the father using G-band technique confirmed a reciprocal balanced translocation between chromosome Y and 15. In the proband, the der (15) has been inherited from the father because the mother had a normal karyotype (46,XX). In the proband, the der (15) could have produced genetic imbalance leading to unbalanced robertson translocation between chromosome Y and 15, which might have resulted in azoospermia and infertility in the proband. The paternal translocation might have lead to formation of imbalanced ova, which might be resulted infertility in the proband. Sister''s karyotypes was normal (46,XX) while his brother was not analyzed.     

Giemsa banding in the t(13q13q) carrier mother of a translocation trisomy 13 abortus

Summary The abortus of a woman who had had three miscarriages and no normal pregnancies had a 46,XX,D-,t(DqDq)+karyotype. The mother was shown to carry the translocation in balanced state; Giemsa banding demonstrated the abnormal chromosome to be t(13q13q)

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Zusammenfassung Die Abortfrucht einer Frau mit 3 Fehlgeburten und keiner normal ausgetragenen Schwangerschaft hat einen Karyotyp 46,XX,D-,t(DqDq)+.Die Mutter hat die gleiche Translokation im balancierten Zustand. Mit Hilfe der Giemsafärbung erwies sich das abnorme Chromosom als t(13q13q).

     

Recurrent proximal 18p monosomy and 18q trisomy in a family with a maternal pericentric inversion of chromosome 18

We report a recurrent partial monosomy of 18p10-->11.2 and proximal partial trisomy of 18q10-->21.3 caused by a maternal pericentric inversion of chromosome 18, involving breakpoints p11.2 and q21q21.3 Based on cytogenetics and FISH analysis, we speculate that the recurrent chromosome abnormality in the proband and in the fetus was the result of a translocation, possibly in a germ cell or germ cell precursor, between the maternal normal 18 and her inverted 18, resulting in maternal germinal mosaicism, i.e. 46,XX,inv(18)/46,XX,t[18;inv(18)][q10;q10]. The unbalanced karyotype of the proband and the fetus is 46,XY,+18,der[18;inv(18)][q10;q10]. To the best of our knowledge, there are no reports of this combination of proximal 18p monosomy and proximal 18q trisomy. The other interesting observation was association of Hirschsprung's disease in the proband.     

Duplication 5q and deletion 9p due to a t(5;9)(q34;p23) in 2 cousins with features of Hunter-McAlpine syndrome and hypothyroidism

We report on 2 similarly affected cousins with a compound imbalance resulting from a familial t(5;9)(q34;p23) and entailing both an ～17-Mb 5q terminal duplication and an ～12-Mb 9p terminal deletion as determined by G-banding, subtelomere FISH, and aCGH. The proband's karyotype was 46,XX,der(9)t(5;9)(q34;p23)mat.ish der(9)t(5;9)(q34;p23)(9pter-,5qter+).arr 5q34q35(163,328,000-180,629,000)×3, 9p24p23(194,000-12,664,000)×1. Her cousin had the same unbalanced karyotype inherited from his father. The clinical phenotype mainly consists of a distinct craniofacial dysmorphism featuring microcephaly, flat facies, down slanting palpebral fissures, small flat nose, long philtrum, and small mouth with thin upper lip. Additional remarkable findings were craniosynostosis of several sutures, craniolacunia and preaxial polydactyly in the proband and hypothyroidism in both subjects. The observed clinical constellation generally fits the phenotypic spectrum of the 5q distal duplication syndrome (known also as Hunter-McAlpine syndrome), except for the thyroid insufficiency which can likely be ascribed to the concurrent 9p deletion, as at least 4 other 9pter monosomic patients without chromosome 5 involvement had this hormonal disorder. The present observation further confirms the etiology of the HMS phenotype from gain of the 5q35→qter region, expands the clinical pictures of partial trisomy 5q and monosomy 9p, and provides a comprehensive list of 160 patients with 5q distal duplication.     

Unbalanced karyotype due to adjacent 1 segregation of t(11;22)(q23.3;q13.2).

The 11q;22q translocations, whatever the breakpoints may be, are of particular interest because of their propensity to 3:1 segregation of the chromosomes at meiosis I. Until now, no unbalanced karyotype resulting from 2:2 adjacent segregation was published among offspring of 11q;22q translocation carriers. The authors report the case of an unbalanced karyotype due to adjacent 1 segregation of a maternal translocation (11;22)(q23.3;q13.2). The proband's karyotype was 46,XX,-22,+der(22)(11;22)(q23.3;q13.2)mat. This finding demonstrates that adjacent 1 segregation is possible in t(11;22) with breakpoints at 11q23 and 22q13, and can lead to birth of viable infants.     

Familial translocation t(10;21)(q22;q22)

Summary A family is described with a translocation t(10;21)(q22;q22) transmitted through three generations. This family was studied for the apparition of several miscarriages and two sisters with multiple malformations. Both children had a probably partial trisomy of chromosome 10 and a monosomy of chromosome 21 due to a maternal adjacent-2 meiotic segregation.     

Mapping breakpoints of a familial chromosome insertion (18,7) (q22.1; q36.2q21.11) to DPP6 and CACNA2D1 genes in an azoospermic male

It is widely accepted that the incidence of chromosomal aberration is 10–15.2% in the azoospermic male; however, the exact genetic damages are currently unknown for more than 40% of azoospermia. To elucidate the causative gene defects, we used the next generation sequencing (NGS) to map the breakpoints of a chromosome insertion from an azoospermic male who carries a balanced, maternally inherited karyotype 46, XY, inv ins (18,7) (q22.1; q36.2q21.11). The analysis revealed that the breakage in chromosome 7 disrupts two genes, dipeptidyl aminopeptidase-like protein 6 (DPP6) and contactin-associated protein-like 2 (CACNA2D1), the former participates in regulation of voltage-gated potassium channels, and the latter is one of the components in voltage-gated calcium channels. The deletion and duplication were not identified equal or beyond 100 kb, but 4 homologous DNA elements were verified proximal to the breakpoints. One of the proband's sisters inherited the same aberrant karyotype and experienced recurrent miscarriages and consecutive fetus death, while in contrast, another sister with a normal karyotype experienced normal labor and gave birth to healthy babies. The insertional translocation is confirmed with FISH and the Y-chromosome microdeletions were excluded by genetic testing. This is the first report describing chromosome insertion inv ins (18,7) and attributes DPP6 and CACNA2D1 to azoospermia.     

Parental Imbalances Involving Chromosomes 15q and 22q May Predispose to the Formation of De Novo Pathogenic Microdeletions and Microduplications in the Offspring

Microarray-based comparative genomic hybridization (array-CGH) led to the discovery of genetic abnormalities among patients with complex phenotype and normal karyotype. Also several apparently normal individuals have been found to be carriers of cryptic imbalances, hence the importance to perform parental investigations after the identification of a deletion/duplication in a proband. Here, we report the molecular cytogenetic characterization of two individuals in which the microdeletions/duplications present in their parents could have predisposed and facilitated the formation of de novo pathogenic different copy number variations (CNVs). In family 1, a 4-year-old girl had a de novo pathogenic 10.5 Mb duplication at 15q21.2q22.2, while her mother showed a 2.262 Mb deletion at 15q13.2q13.3; in family 2, a 9-year-old boy had a de novo 1.417 Mb deletion at 22q11.21 and a second paternal deletion of 247 Kb at 22q11.23 on the same chromosome 22. Chromosome 22 at band q11.2 and chromosome 15 at band q11q13 are considered unstable regions. We could hypothesize that 15q13.2q13.3 and 22q11.21 deletions in the two respective parents might have increased the risk of rearrangements in their children. This study highlights the difficulty to make genetic counseling and predict the phenotypic consequences in these situations.     

A novel combined 15q11.2 duplication and a bisatellited supernumerary marker derived from chromosome 22: Molecular characterization of the marker

Supernumerary marker chromosomes (SMC) are heterogeneous group of chromosomes which are reported in variable phenotypes. Approximately 70% originate from acrocentric chromosomes. Here we report a couple with recurrent miscarriages and a SMC originating from an acrocentric chromosome. The cytogenetic analysis of the husband revealed a karyotype of 47,XY+marker whereas the wife had a normal karyotype. Analysis of SMC with C-banding showed the presence of a big centromere in the center and silver staining showed prominent satellites on both sides of the marker. Apparently, microarray analysis revealed a 2.1 Mb duplication of 15q11.2 region but molecular cytogenetic analysis by fluorescence in situ hybridization (FISH) with whole chromosome paint (WCP) 15 showed that the SMC is not of chromosome 15 origin. Subsequently, FISH with centromere 22 identified the SMC to originate from chromosome 22 which was also confirmed by WCP 22. Additional dual FISH with centromere 22 and Acro-p-arm probes confirmed the centromere 22 and satellites on the SMC. Further fine mapping of the marker with Bacterial Artificial Chromosome (BAC) clones; two on chromosome 22 and four on chromosome 15 determined the marker to possess only centromere 22 sequences and that the duplication 15 exists directly on chromosome 15. In our study, we had identified and characterized a SMC showing inversion duplication 22(p11.1) combined with a direct tandem duplication of 15q11.2. The possible genotype–phenotype in relation with the two rearrangements is discussed.     

Double autosomal aberration: trisomy 21 and familial reciprocal translocation t(10;12)(p14;q21)]

A child with the Down syndrome revealed besides a regular trisomy 21, an enlargment of the short arm of chromosome 10, and the deletion of the long arm of chromosome 12. The proband's mother, who was phenothypically normal woman, appeared to be a carrier of the reciprocal translocation, her karyotype being: 46, XX, rep (10;12) (10qter leads to leads to 10p14; 12q21 leads to 12qter; 12pter leads to 12q21 : 10p14 leads to 10pter). Hence, the proband had double chromosomal aberration 47, XX, +21, rcp (10; 12) (10qter leads to 10p14 : 12q21 leads to leads to 12qter; 12pter leads to 12q21 : 10p14 leads to 10pter) mat. There is no reason to relate hard manifistation of the Down syndrome with the detected translocation. The influence of the mathernal non-devision in the meiosis and the rise of the trisomy 21 is discussed. In the following pregnancies it is advisable to amniocentesis.     

Spectral karyotyping and fluorescence in situ hybridization analysis of de novo partial trisomy 7p (7p21.2-->pter) and partial monosomy 12q (12q24.33-->qter)

An 8-year-old boy presenting with hypotonia, moderate mental retardation, developmental delay, and psychomotor retardation is reported. Magnetic resonance imaging of the brain at age 3 years revealed a Dandy-Walker variant. Cytogenetic analysis of the peripheral blood revealed a derivative chromosome 12 with unknown additional material attached to the distal region of the long arm of chromosome 12. The parental karyotypes were normal. Spectral karyotyping (SKY) using the 24-color SKY probes and fluorescence in situ hybridization (FISH) using the specific 7p, 7q, 12p, and 12q telomeric probes confirmed a duplication of distal 7p and a deletion of terminal 12q. The karyotype of the proband was designated as 46,XY.ish der(12)t(7;12) (p21.2;q24. 33)(SKY+, 7pTEL+, 12qTEL-). The present case provides evidence for the association of partial trisomy 7p (7p21.2-->pter) and partial monosomy 12q (12q24.33-->qter) with a cerebellar malformation and the usefulness of SKY and FISH in the identification of a de novo aberrant chromosome resulting from an unbalanced translocation.     

Inheritance of a translocation between chromosomes 12 and 16 in a family with recurrent miscarriages and a newborn with Down syndrome carrying the same translocation

Reciprocal translocation carriers have reduced fertility, increased risk of spontaneous abortion or unbalanced karyotype in their offspring. Here, we report the inheritance of a translocation between chromosomes 12 and 16 in a family with recurrent miscarriages and a newborn with Down syndrome carrying the same translocation. Chromosomal analysis from fetal amniotic fluid and peripheral blood lymphocytes from the family were performed at the Cukurova university hospital in Turkey. We assessed a family in which the translocation between chromosomes 12 and 16 segregates; one of the eight progenies with the karyotype 47,XY,+21,t(12;16)(q24;q24) was heterozygote for the translocation and presented with Down syndrome. His mother is phenotypically normal, one brother and one sister were also carrying the same translocation. Apparently, this rearrangement occurred due to the unbalanced chromosome segregation of the mother [t(12;16)(q24;q24)mat]. This case will enable us to explain the behavior of segregation patterns and the mechanism for each type oftranslocation from carrier to carrier and their effects on reproduction and numerical aberrations. The t(12;16) is also associated with fetal wastage and may play a role in the etiology of the family's miscarriages. These findings can be used in clinical genetics and may be used as an effective tool for reproductive guidance and genetic counseling.     

A rare insertional translocation of proximal segment with heterochromatic region of 1q into 7p in monozygotic twins and spontaneous abortions

Summary We present a family identified through a healthy 20-year-old female with a history of multiple successive spontaneous abortions. Her karyotype demonstrates a rare balanced insertional translocation between chromosomes 1 and 7, 46,XX,dir ins(7;1)(p15.3;q12q21.3). This is the first reported case of a 7;1 insertional translocation involving the proximal segment of chromosome 1 and may well be the cause of the multiple spontaneous abortions in our proband.     

Lethal polymalformative syndrome with 13q deletion secondary to a maternal X; 13 translocation

The authors report the case of a newborn full term delivered by cesarean section for evolutive hydrocephalus, in the last month of pregnancy. This hydrocephalus was confirmed by echography after birth. This also having ambiguous genitalia and atresia ani, he died a few hours later. No evidence of infectious or toxic embryofetopathy was found out as an etiologic factor, but the karyotype of the baby showed a 13 q deletion and that of the mother a non reciprocal Xqter; 13q31.3 translocation. The study of inactivation of X indicated that the inactivated X chromosome in each cell was normal. On this occasion, the authors try to bring together the main points of "13q-syndrome" and discuss on the practical approach of antenatal diagnosis which they could propose to the couple.     

Prenatal diagnosis of de novo unbalanced translocation 8p;21q using subtelomeric probes

We report an unbalanced translocation involving chromosomes 8 and 21 in a fetus showing ultrasonographic abnormalities in the second trimester of pregnancy. A 41-year-old pregnant woman, gravida 1 para 0, was referred to the Genetics Clinic at the 16th week of gestation because of advanced maternal age and fetal pelvicaliectasis on ultrasonographic examination. Pregnancy had occurred following ICSI treatment. After genetic counseling amniocentesis was performed. Fetal karyotype analysis revealed a 46,XY,8p+ karyotype. Ultrasonographic examination was repeated at the 20th week of gestation and showed intrauterine growth retardation, ventriculomegaly, cerebellar structural abnormality and pelvicaliectasis. Chromosomes of both parents were normal. Molecular cytogenetic studies (FISH) using chromosome-specific subtelomere probes showed a terminal deletion of 8p and trisomy of the 21q subtelomeric region. Further analysis with Down Syndrome specific region probes revealed two signals. The couple decided to terminate the pregnancy. This is the first prenatally diagnosed case of unbalanced t(8p;21q) of de novo origin.