Partial trisomy 11 in a child resulting from a complex maternal rearrangement of chromosomes 11, 12 and 13

Summary A complex structural rearrangement of chromosomes 11, 12 and 13 was found in a normal female who gave birth to an affected child with partial trisomy for the short arm of chromosome 11 and a balanced translocation 12/13. The detailed analysis of the G-banded chromosomes from early metaphases permitted the delineation of new chromosomal bands which in turn proved essential to the identification of this unusual phenomenon.

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Zusammenfassung Bei einer normalen Frau, die ein Kind mit partieller Trisomie des kurzen Armes des Chromosoms 11 und eine balancierte Translokation 12/13 hatte, wurde ein kompliziertes strukturelles Rearrangement der Chromosomen 11, 12 und 13 gefunden. Eine detaillierte Analyse der Chromosomen nach Darstellung der G-Banden aus frühen Metaphasen erlaubte die Abgrenzung neuer Chromosomenbanden, die sich ihrerseits als notwendig für die Analyse dieses seltenen Phänomens erwiesen.

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This work was partly supported by research Grant No. HD-01962 from the National Institutes of Health.     

Partial trisomy 16q resulting from maternal translocation

Summary A 3 1/2-year-old male with partial trisomy of the long arm of chromosome 16 resulting from a maternal balanced translocation is described. Karyotype: 46,XY,-22,der(22),t(16;22)(q21;p12)mat.     

Partial trisomy 16q resulting from maternal translocation 11p/16q

A 3 1/2-year-old male with partial trisomy of the long arm of chromosome 16 resulting from a maternal balanced translocation 11p;16q is described. Clinical findings are compared with similar case reports from the literature.     

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.     

Partial trisomy for the segment 21(q11----qter) resulting from a de novo translocation between chromosomes 5 and 21

A 3 1/2-year-old boy is described whose Down syndrome resulted from partial 21 trisomy through unbalanced de novo translocation between the long arm of chromosome 21 and the short arm end of a No. 5: 46,XY,t(5;21)(p15;q11). This case is discussed and compared with 17 others collected from the literature, some of which derived from a maternal balanced translocation.     

Partial trisomy 11,46,XX,-3,-20,+der3,+der20,t(3:11:20), resulting from a complex maternal rearrangement of chromosomes 3, 11, 20

Summary Clinical findings of partial trisomy 11p are described in a patient bearing t(3;11;20) (p13;p11;q13). The translocation was present in balanced form in her mother (46,XX)t(3;11;20)(p13;p11;q13).     

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.     

Partial distal trisomy 13q resulting from familial reciprocal 5/13 translocation

Summary A female infant with partial trisomy 13, 46,XX,der(5),t(5;13) (p15;q22)mat, for the distal part of the long arm is reported. The clinical and autopsy findings were similar to those of complete trisomy 13, except for harelip and cleft palate, and sloping forehead. Fetal hemoglobin and nuclear appendages in polymorphonuclear leukocytes were normal. Loci for these traits are discussed.     

Partial trisomy 20p derived from a t(18;20) translocation

Summary Two sibs show a strikingly concordant syndrome of congenital anomalies and G-banding reveals that each has partial trisomy 20p resulting from a t(18;20) translocation. They resemble other cases of partial trisomy 20p in some respects but also differ in some ways. Their normal sib, mother, and half-aunt are balanced heterozygotes for the t(18;20) translocation. The segregation of the balanced translocation in this family is associated with an extremely poor reproductive record. The segregation pattern closely parallels that of a t(13;20) translocation in a family described by Carrel et al. (1971) and Francke (1972). The similarity of segregation patterns is predictable on the basis of probable pachytene configurations, but the dissimilarity of phenotypes between families is not readily explained.     

Partial trisomy 13 due to maternal translocation t(2;13)]

The authors report an observation of partial trisomy 13p13 leads to qter and suggest a clinical map of chromosome 13. Increase of fetal hemoglobin seems to be controlled by region 1 of 13q. Bands q13 q14 and q21 seem to be responsible for inner organ malformations. Lastly, the distal segment q22 leads to qter is responsible for trigonocephaly and limb abnormalities.     

Partial trisomy 18q in a newborn with typical 18 trisomy phenotype

Summary This paper describes a case of partial trisomy of almost the entire long arm of chromosome 18 in a newborn with classic trisomy-18 phenotype, resulting from a de novo unbalanced 18q/21p translocation: karyotype: 46,XX,-21,t(18;21)(18qter18q11::21p1221qter). A review of the other reported cases of partial trisomy 18 suggests that a critical segment in chromosome 18, corresponding to bands q11-q12, might be responsible for most of the signs of trisomy 18, including failure to thrive and early death.     

Partial trisomy 4(q31qter) due to maternal 4;5 balanced translocation in a neonate

We describe a male neonate with a duplication of 4(q31.3qter) due to unbalanced segregation of a maternal translocation (4;5)(31.3;p15.1). He has a high broad nasal bridge, large, low-set ears, epicanthal folds, long philtrum, retrognathia, high arched palate, wide-spaced nipples, bilateral single transverse palmar creases, bilateral clinodactyly of the fifth finger, right cryptorchidism, and ventricular and secundum type atrial septal defect.     

Partial 9q trisomy associated with a 9,21 translocation

Summary A new case of partial trisomy 9q was found in a child presenting two de novo aberrations: a deletion of the long arms of 9 and a 9,21 translocation. A tentative cytogenetic explanation is put forward.