Two cases of del(13q)-retinoblastoma and two cases of partial trisomy due to a familial insertion

A del(13)(q13q21.1) was found in a patient with bilateral retinoblastoma and mental retardation. The father was carrier of an ins(16;13)(q12.2;q13q21.1) which also was present in several other family members, and responsible for another case of del (13q)-retinoblastoma and two cases of trisomy for the inserted segment. This second del(13q) patient was also carrier of a balanced t(11;22).     

2 cases of partial trisomy 10p due to a paternal translocation t(10p;18)(p13;q23)]

Two brothers trisomic for the distal two thirds of 10p are reported. Trisomy results from the malsegregation of a familial translocation rcp (10;18)(p13;q23) present in the father, a half-brother and the grand-father of the propositi. The phenotype is comparable to that of other 10p trisomic patients reported in the literature.     

Partial trisomy 4q due to familial 2/4 translocation

Summary The case of a 5-year-old boy with partial trisomy for the long arm of chromosome No. 4 is described. The pattern of abnormal development in this and in 12 previously reported cases is similar, but the phenotype is not as characteristic as that associated with some other types of chromosomal imbalance. The most consistent features are: growth and mental retardation, small head with narrow forehead, short philtrum, relatively large ears with incomplete differentiation of the pinnae, cryptorchidism, oedema of the hands and/or feet, and renal anomalies. Abnormal development of the thumb was present in 4 of 13 cases. Eleven of the 13 families had balanced translocation carriers whose future offspring would be at increased risk for a mental retardation syndrome.     

Two new cases of trisomy 10q21 to 10qter in two sisters due to paternal translocation t(9;10) (q34;q24)]

Two sisters with multiple congenital malformations were shown to be trisomic for 10q24 to 10qter as a consequence of malsegregation of the balanced paternal translocation t(9;10) (q34;q24). Comparison of their phenotype with that of other patients reported in the literature confirms the individuality of the partial 10q trisomy syndrome.     

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.     

Partial trisomy 17q and monosomy 9p due to a familial translocation.

Described is an infant with partial trisomy 17q and monosomy 9p [46,XX,-9,+der(9)t(9;17)(p21;q23)] due to adjacent-1 segregation of a maternal balanced reciprocal translocation. Characteristic clinical features of both partial 17q trisomy and monosomy 9p are present, but the former syndrome is less recognisable in this infant than in previously reported cases due to the concomitant 9p monosomy.     

Two familial cases with trisomy 15q dist due to a rcp(5;15)(p14;q21)

Summary A trisomy of the distal long arm of chromosome 15 (q21qter) resulting in similar phenotypic and developmental abnormalities in two related children (a boy and a girl) is described. The chromosome defect was due to malsegregation of a balanced translocation (5;15)(p14;q21) in one of the parents. It was inherited in four generations and accompanied by recurrent miscarriages. Comparison of these patients with four previously published cases of trisomy 15q dist reveals a pattern of common features including: microdolichocephaly with characteristic strikingly protuberant occiput and predominance of the visceral over the cerebral cranium; peculiar facial dysmorphism—narrow antimongoloid palpebral fissures; large, malformed, low-set ears; micrognathy; long philtrum; short neck; cardiopathy; profound encephalopathy with lack of suck and swallow reflexes; and no growth retardation.     

De novo appearance of a partial trisomy 1q in mosaic due to a 1;9 translocation

A child with trisomy 1q24----qter is described. This syndrome is compared to other 1q partial trisomies. An association is proposed between these trisomic segments and the following phenotypic signs: microphtalmia, trigonocephaly, hypertrichosis, antimongoloid eye slants, anomalies of the biliary tract, and malformations of the central nervous system.     

Partial trisomy 14q due to familial t(14q-, 11q+) translocation

Summary A malformed male newborn with partial trisomy for the distal part of the long arm chromosome 14 (14q₂₃14qter) is described. This anomaly arose as a segregation product of a balanced t(14q-, 11q+), translocation in the father.     

Partial trisomy 4q: Two cases resulting from a familial translocation t(4;18)(q27;p11)

Summary Partial trisomy of the long arm of chromosome 4 was observed in two related patients, a child aged 2 years and a woman aged 42. Cytogenetic investigation revealed that their chromosome anomalies were due to segregation of a familial balanced translocation t(4;18)(q27;p11). Some clinical and cytogenetic considerations are noted.     

Secondary trisomy 1 q due to a reciprocal maternal translocation]

The authors report a case of partial trisomy 1 q due to a maternal balanced translocation : t(1 ; 4) (q 32 : p 16). The evocative malformations of trisomy 1 q and monosomy 4 p are discussed and compared to seven others from the literature. Then the interest of the chromosomical prenatal diagnosis and the significance of familial genetic studies are showed.     

A partial trisomy 15q due to 15;17 translocation detected by conventional cytogenetic and FISH techniques

We report a case having multiple abnormalities including the simultaneous presence of the heart defect and central nerve system abnormalities, which has been reported in a few cases, and with a partial trisomy 15q. Partial trisomy 15q has been inherited from a balanced translocation carried by his phenotypically normal father, detected by traditional banding and fluorescence in situ hybridization (FISH). Application of FISH using whole chromosome specific library probes, locus specific and repetitive probes allowed us to detect the translocation between chromosomes 15q and 17q. Simultaneous application of probes revealed the position of the translocation. Interestingly, in addition to the chromosomes 15 pericentromeric signals, the use of chromosome 15 beta-satellite III probe demonstrated an extra signal on chromosome 14 in both metaphase, and lighted three signals interphase nuclei which was inherited from his father. This patient is compared with other partial trisomy 15q patients reported in the literature. The results are also discussed in relation to genetic counselling for the possible relation of chromosome abnormality and clinical findings.     

Partial trisomy 6p due to familial translocation t(6;20)(p21;p13)

Summary Cytogenetic findings in a case of partial trisomy 6p due to a translocation t(6;20)(p21;p13) and eleven balanced translocation heterozygotes are described.The clinical data of the proposita are compared with those of five other published cases. A partial trisomy 6p syndrome is postulated, characterized by: low birth weight, psychomotor retardation, craniofacial abnormalities (such as high prominent forehead, large fontanel, wide sagittal suture, blepharoptosis, low-set and/or malformed ears), congenital heart malformation, small kidneys, and proteinuria. Linkage studies have shown that the breakpoint in chromosome 6 involved in this translocation is close to the HLA gene cluster.     

Partial trisomy 14q and familial translocation (2;14) (q12;q13).

A female patient with moderate psychomotor retardation, minor anomalies and proximal trisomy 14q due to segregation of a maternal translocation is reported.     

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.