Partial trisomy 2q and familial translocation t(2;12)(q31;q24)

Summary Report is given of a boy with trisomy of the distal part of the long arm of chromosome 2 (q31ter) due to a balanced 2/12 translocation in the mother: 46,XX,t(2;12) (q31;q24). Other phenotypically normal carriers of this balanced translocation are the patients sister and grandfather. The patient shows a variety of dysplastic signs mainly of the face.     

Translocation (Y;19)(q12;q13) and azoospermia

An azoospermic male with a 46,X,t(Y;19)(q12;q13) karyotype is described. The comparison with 12 similar cases reveals that the Y breakpoints are usually on the long arm whereas the autosomal ones seem to be at random. Since a premeiotic origin is inconsistent with the arrest at diakinesis seen in those cases with meiotic studies, we postulate that a balanced t(Y;A) arises either via a chromatid exchange in the meiotic interphase or through a chromosome exchange in spermiogenesis or at the one cell stage of the zygote.     

Partial trisomy of distal 5q and partial monosomy of Xp as a result of mating between two translocation carriers: a female with a balanced translocation t(X;5)(p11;q31) and a male with a der(13;14)(q10;q10)--a case report and a family study

This paper presents the family of a dysmorphic child with the phenotypic features of Turner's syndrome and 5q trisomy, whose parents are both carriers of a balanced translocation. The parents' karyotypes are 46,X,t(X;5)(p11.1;q31) and 45,XY,der(13;14)(q10;q10), respectively.     

A jumping translocation (5p;15q), (8q;15q), and (12q;15q) (author's transl)]

Three balanced karyotypes (5p;15q), (8q;15q), and (12q;15q) were found simultaneously in a child with the Willi-Prader syndrome. The hypothesis is presented of a "jumping# translocation by affinity of telomeric and interstitial palindromes. The relationship between the Willi-Prader syndrome and a juxtacentric anomaly of the long arm of chromosome 15 is discussed.     

Partial 4q duplication due to Inherited der(13),t(4;13)(q26;q34)mat in a girl with a deficiency of Factor X

A girl with mental retardation had a partial trisomy 4q. The chromosome aberration originated from a maternal balanced translocation t(4;13)(q26;q34). The value for Factor X was half the normal value, raising the question of the location of a gene related to the production of Factor X on chromosome 4.     

De novo balanced translocation (2;10)(q24;q22) associated with mental retardation

We report a case of a reciprocal translocation between the long arms of the 2 and 10 chromosomes observed in a 14-year-old male with mild mental impairment, compulsive and obsessive behavior. The apparently balanced translocation was characterized by fluorescence in situ hybridization and the karyotype was 46, XY, t(2;10)(q24;q22). The way by balanced chromosomal translocations can lead to a disease phenotype are reviewed and discussed.     

De novo t(2;13)(p24.3;q14.2) and retinoblastoma

Summary The two probes H3-8 and H2-42, known to be located in 13q14, were mapped by in situ hybridization to either side of the 13 breakpoint of an apparently balanced de novo t(2;13)(p24.3;q14.2) detected in a patient with retinoblastoma as the only phenotypic manifestation.     

Partial trisomy 4q: Two cases with a familial translocation t(4;18)(q27;q23)

Clinical and cytogenetic data of two related patients, both trisomic for the segment 4q27 to qter, are reported. Familial studies determined that the mothers of the two probands were carriers of the same balanced translocation between chromosomes 4 and 18. Altogether, two partial trisomies 4q, five balanced karyotypes, and one 45,X0 karyotype were found in the family. The 18 cases reported to date are reviewed with respect to the karyotype-phenotype correlation.     

A Turner patient with a 45,X,t(1;2) (q41;p11.2) karyotype

The most common chromosomal anomaly is 45,X in the Turner syndrome. In addition to this, anomaly, mosaicism such as structural 46,X,i(Xq), 46,X,del(Xp), 46,X,r(X), 46,X,t(X;Y) and numerical 46XO/46,XX/47XXX are seen rather frequently. An infant with the Turner syndrome was found to have a karyotype 45X,t(1;2) (q41;p16) using high resolution banding. Based on our knowledge, we present the first case of 45X,t(1;2) (q41;p11.2), a karyotype in Turner's syndrome in the literature.     

A t(X;15)(q23;q25) with Xq reactivation in a lymphoblastoid cell line from Fanconi anemia.

A t(X:15)(q23;q25) was detected during cytogenetic investigation of a lymphoblastoid cell line established from a female patient with Fanconi anemia. The translocation was apparently balanced at passage 300 and unbalanced at passage 13. A chromatid exchange between both the normal and the der(15), between the centromere and band 15q25, may explain these results. Replication studies, following BrdU incorporation, indicate that the segment Xq23----qter from the der(15) is early replicating whereas segment Xpter----q23 from the der(X) is late replicating. Since the normal X was early replicating, it is concluded that the segment of the long arm of chromosome X, separated from its inactivation center by the translocation, was reactivated. This interpretation is confirmed by the methylation patterns of the hypoxanthine phosphoribosyltransferase gene (HPRT), mapped on Xq26, which corresponds to that of an active gene, whereas that of phosphoglycerate kinase (PGK1), which remained on the der(X), corresponds to that of an inactive gene. This is the first example of reactivation of a segment of the X chromosome following a structural rearrangement in somatic cells.     

47,XY,+der(11;22)(q23;q12) following balanced translocation t(11;22)(q23;q12)mat

Summary Report of a supernumerary extra chromosome der(11;22)(q23; q12) resulting from a balanced translocation in the mother. The propositus suffers from mental deficiency, deafness and extreme muscular weakness and exhibits cleft palate, a labial lymphangioma and an atrial septum defect. Since the features of partial trisomy 11q23 frequently associated with a translocation t(11q;22q) bear similarities with the cases of so called trisomy 22 one might conjecture that some of these observations are in fact products of translocations including partial 11q.     

Analysis of segregation and aneuploidy in two reciprocal translocation carriers, t(3;9)(q26.2;q32) and t(3;9)(p25;q32), by triple-color fluorescence in situ hybridization

Meiotic segregation patterns of chromosomes 3 and 9 were analyzed in sperm of two translocation carriers (t(3;9)(q26.2;q32) and t(3;9)(p25;q32)) by triple-color fluorescent in situ hybridization (FISH) with a telomeric DNA probe in addition to two centromeric probes. The frequencies of each sperm product resulting from alternate or adjacent I, adjacent II and 3:1 segregation in a t(3;9)(q26.2;q32) translocation carrier were 88.35%, 5.44% and 5.94%, respectively. On the other hand, the frequencies of each sperm product in a t(3;9)(p25;q32) translocation carrier were 89.23%, 6.02% and 4.48%, respectively. Of all the sperm products, the frequency of normal or chromosomally balanced sperm in a t(3;9)(q26.2;q32) and a t(3;9)(p25;q32) were 52.49% and 47.25%, respectively. The frequencies of each sperm product resulting from various segregations were different between both carriers and significantly deviated from the expected frequencies. Additional dual-color and triple-color FISH were performed to analyze aneuploidy rates for chromosomes 12, 17, 18, X and Y in order to detect any interchromosomal effect; no evidence of an interchromosomal effect was found.     

2:12 (p25;q21) translocation classed at first as 2/X]

A balanced translocation t(2;12)(p25;q21) was observed in a girl with mental retardation and several somatic abnormalities. The problems of phenotype-karyotype correlations are discussed.     

Partial trisomy of chromosome 21 by maternal translocation t(15;21) (q26.2; q21)]

A balanced reciprocal translocation, t(15;21) (q262;q21) was observed in the mother and maternal grandfather of two patients. The propositus, who received the abnormal chromosome 15 from his mother, is trisomic for the distal part of chromosome 21, and his phenotype is that of classical trisomy 21. His sister, who is trisomic for the proximal part of 21q, is slightly retarded but developmentally normal otherwise.     

Inherited Xq duplication due to a zygotic translocation t(X;X)(q23;q27)

An Xq-duplication was found in a female child with multiple malformations. The family study revealed that her mother, who has a nearly normal phenotype, carries the same duplication. The karyotype of the grandmother shows the existence of a mosaicism: 46,X,del(X) (q23)/46,X,dup(X)(q27----q23). This mosaicism can be related to a translocation t(X;X)(q23;q27) during the first cell division of the zygote.     

A case of Alagille's syndrome with translocation (4;14) (q21;q21)

This paper reports a case of Alagille's syndrome, in association with a translocation 46,XY,t(4;14)(q21;21). The possible relationship between this autosomal dominant syndrome and the apparently balanced chromosomal rearrangement is discussed.     

Partial duplication 14q/deletion 2q in two sibs due to t(2;14) (q37.1;q31.2) pat

Two siblings are described with duplication 14q/deletion 2q due to a paternal translocation (2;14) (q37.1;q31.2). The first one, a boy, born at term, lived 14 days. The second one, a female foetus, was born after induced labour when the anomaly was discovered by way of amniocentesis. They both had almost identical phenotypes. From a study of the literature it is inferred that a typical asymmetric head form, low set abnormal ears, micrognathia, long upper lip, rib anomalies, camptodactyly, long fingers and contractures are prominent features of the syndrome.     

Partial trisomy of the long arm of chromosome 2 by malsegregation of a maternal translocation t(2;7)(q321;p22)

A patient with partial trisomy 2q due to the malsegregation of a balanced maternal (2;7) translocation is reported. The proposita, who died a few hours after birth, presented the characteristic clinical features: microcephaly, prominent forehead, hypertelorism, depressed nasal bridge, upturned nostrils. Her karyotype was 46,XX,der(7),t(2;7)(q321;p22) mat.