Partial trisomy 15q due to maternal translocation t(7;15)(q35;14)]

Partial trisomy for the long arm of chromosome 15 was detected in a 21-year-old girl with severe growth and mental retardation. A balanced reciprocal translocation - t(7;15)(q35;q14) - is present in the mother.     

Trisomy 20p: case report and genetic review

Partial trisomy for the distal part of the short arm of chromosome 20 reported in a girl aged 11/2 years with typical craniofacial dysmorphies and psychomotor retardation. The trisomy resulted from a paternal translocation t(14;20) (q32.3;p11.1). The review of 25 cases of partial trisomy 20p showed that most cases (22 : 25) were due to parental translocations. Predominant involvement of small chromosomes in translocations with chromosome 20 was also detected.     

Partial trisomy for the long arm of chromosome 7 due to familial balanced translocation

Summary A partial trisomy for the distal segment of the long arm of chromosome 7 (bands q32qter) was observed in a severely retarded child with somatic and CNS anomalies. The phenotypically normal father and paternal grandmother had a balanced reciprocal translocation between the long arm of a chromosome 2 and the long arm of a chromosome 7: 46,XX-XY,t(2;7) (q37;q32). The clinical features of the child at birth and at the ages of 5 months and 2 years are compared with those previously reported in cases of partial trisomy 7q.     

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 for the short arm of chromosome 2 due to familial balanced translocation

Summary A partial trisomy for the short arm of chromosome 2 (p21pter) was observed in a severely retarded infant with facial, skeletal, genital, renal, and CNS anomalies. The phenotypically normal mother and older brother had a balanced translocation between the short arm of chromosome 2 and the long arm of chromosome 14: 46,XX-XY,t(2;14)(p21;q32).     

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.     

Distal trisomy 14 (q24 --> qter) and aorto-pulmonary window: a case report and review of the literature

A newborn female with partial trisomy for the distal part of the long arm of the chromosome 14 (14q24 --> qter) resulting from a paternal balanced translocation (3;14) is described. We compare her phenotype with eight other individuals with trisomy 14q24 --> qter.     

Duplication 11 (q22----qter) in an infant. A case report with review

A male infant with partial duplication of the long arm of chromosome 11 (11q22----qter) is described with a hitherto unreported translocation. In most cases 11q trisomy is associated with 11q/22q translocation and a 3:1 meiotic disjunction with 47 chromosomes. In a few cases the 11q translocation is associated with a partial deletion of other autosomes and a total of 46 chromosomes. In the present case, translocation to 9p is involved and no apparent deletion of 9p was noted, providing an opportunity to delineate the phenotypic features due to duplication of 11q. A comparison is made between the findings of partial 11q trisomy and 11q/22q translocation.     

Partial proximal trisomy 10q syndrome: a new case

We report a case of partial proximal trisomy of the long arm of chromosome 10 confirmed by fluorescence in situ hibridization (FISH) performed with whole chromosome 10 specific painting and specific yac clones. The phenotypic findings, compared to those found in other published cases with the same karyotype, support the recognition of a distinctive partial proximal trisomy 10q syndrome (10q11-->q22).     

Unbalanced 1q whole-arm translocation resulting in der(14)t(1;14)(q11-12;p11) in myelodysplastic syndrome

Unbalanced whole-arm translocations (WATs) of the long arm of chromosome 1, resulting in complete trisomy 1q, are chromosomal abnormalities detectable in both solid tumors and hematologic neoplasms. Among the WATs of 1q to acrocentric chromosomes, a few patients with der(1;15) described as a dicentric chromosome have been reported so far, whereas cases of der(1;14) are much rarer. We report on a case of der(1;14) detected as single anomaly in a patient with myelodysplastic syndrome. The aim of our work was to investigate the breakpoints of the (1;14) translocation leading to the der(1;14). Fluorescence in situ hybridization (FISH) experiments have been performed on chromosome preparations from bone marrow aspirate, using specific centromeric probes of both chromosomes, as well as a probe mapping to 1q11 band. FISH results showed that in our patient the derivative chromosome was monocentric with a unique centromere derived from chromosome 14. The breakpoints of the translocation were located in the short arm of chromosome 14 and in the long arm of chromosome 1, between the alphoid D1Z5 and the satellite II domains. The 1q breakpoint was within the pericentromeric region of chromosome 1, which is notoriously an unstable chromosomal region, involved in different chromosomal rearrangements.     

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.     

Distal trisomy 10q/partial monosomy 14q: an unusual clinical picture

A case of twin boy with partial trisomy for the distal part of the long arm of chromosome 10 (10q24-->qter) and a concomitant monosomy 14(q32-->qter) is reported. The chromosomal abnormalities resulted from a paternal balanced translocation involving chromosomes 10 and 14. An additional clinical feature was observed, viz. hypoplastic lungs. The proband's phenotype was compared to previously reported patients with partial trisomy 10q or 14q deletion.     

Trisomy 4q syndrome: presentation of a new case and review of the literature

We describe the 11th case of a de novo partial trisomy of the long arm of chromosome 4, with the extra segment spanning from 4q27 to 4q35. The aberration resulted from an unbalanced translocation of material from 4q to the short arm of chromosome 7, as evident from fluorescent in situ hybridization. Microsatellite analysis revealed the extra material to originate from the father. The karyotype was interpreted as 46,XX,der(7)t(4;7)(q27;p22). The patient is a 13-year-old girl with severe mental retardation, growth retardation, hearing impairment as well as minor foot, thumb and facial anomalies. Although the extent of the aberration varies between the reported patients, there are nevertheless features in common, suggestive of a trisomy 4q syndrome. The clinical findings most frequently reported are: mental retardation, seizures, microcephaly, hearing impairment and growth retardation, as well as epicanthic folds, high/broad/depressed nasal bridge, malformed ears, tooth and thumb anomalies. Almost the entire long arm of chromosome 4, except band q11, has been involved in trisomies/duplications, but 4q27 and 4q31 seem to be preferentially engaged in the trisomy 4q syndrome.     

Trisomy 6q22 leads to 6qter due to maternal 6;21 translocation. Case report review of the literature

Partial trisomy for the long arm of chromosome 6, involving 6q22 leads to 6qter, was observed in a 2-month-old male infant. The mother was 6q;21p translocation carrier. A review of the previously published cases with trisomies of different 6q segments suggests that the critical segment responsible for the clinically recognizable phenotype of 6q trisomy seems to be limited to bands 6q26 and/or 6q27.     

Partial trisomy of chromosome no. 1 in two adult brothers due to maternal translocation (1q-;6p+)

Summary Extra chromosome material on the short arm of chromosome no. 6 (46,XY,6p+) was found in two mentally retarded adult half-brothers with mildly dysmorphic features. The phenotypically normal mother had a balanced translocation between the long arm of chromosome no. 1 and the short arm of chromosome no. 6: 46,XX,t(1;6)(q32;p25). Thus the two affected brothers were trisomic for the long arm segment of chromosome no. 1, distal to q32. These patients, with mildly dysmorphic features and mental retardation, represent the first cases of partial trisomy 1q surviving to adulthood.The clinical and cytogenetic data obtained from eight individuals with partial trisomies for different long arm segments of chromosome no. 1 suggest that partial trisomy of the distal two-thirds of the long arm is characterized by severe malformations, growth retardation, and early death. Conversely, partial trisomy for the distal one-third of the long arm is associated with milder malformations and longer survival time as well as growth and mental retardation.     

Partial trisomy of 13(pter→q12) due to 47,XY,+der(13),t(13;22)(q12;q13)mat

Summary A 36-month-old boy presented with short stature, short neck, shield-shaped chest, and mental retardation. Chromosome analysis showed trisomy for the short arm and the proximal portion of the long arm of chromosome 13 [47,XY,+der(13),t(13;22)(q12;q13)mat]. The patient's mother has a balanced translocation between the long arms of chromosomes 13 and 22 [46,XX,t(13;22)(q12;q13)]. The patient's neutrophils showed an elevated number of nuclear projections and his fetal hemoglobin level was undetectable.     

Tertiary trisomy of 10p15.pter and 14pter.ql3 due to maternal translocation t(10;14)(p15;q13)

Double partial trisomy resulting from 3:1 segregation of the respective chromosomal segments of the chromosomes involved in a balanced translocation in meiosis is rarely reported in the literature. We present here a first patient with multiple congenital malformations associated with double partial trisomy of 10pter-p15 and 14pter-q13 resulting from 3:1 segregation of maternal balanced translocation t(10;14)(p15;q13). Proximal partial trisomy of chromosome 14 and subterminal trisomy of the short arm of the chromosome 10 are rare. The present case is the first case with double partial trisomy of these segments resulting from 3:1 segregation of a maternal balanced translocation.     

Distal trisomy 14q

Two cases of de novo duplication of the distal part of the long arm of chromosome 14 are reported. In one case, the partial trisomy of 14q is due to translocation of a segment (14q24 to 14qter) at the end of the satellite stalk of chromosome 14. The clinical picture is very severe. In the second case, a tandem duplication in 14 (q23----q32) is present with only minor malformations and mild mental retardation.     

Partial trisomy of the distal part of 10q: a report of two Egyptian cases

Partial trisomy of the distal third of the long arm of chromosome 10 is a well defined but rare syndrome. Most cases result from an unbalanced translocation. Growth retardation, developmental delay and characteristic dysmorphic features are well described in the syndrome. This report includes 2 Egyptian cases with partial 10q trisomy involving different breakpoints. Cases were subjected to full clinical examination and detailed cytogenetic analysis using conventional and FISH studies. Results showed that the karyotype of case 1 was 46,XX,der(7)t(7;10)(p22;q23).ish(wcp7+;wcpl0+) and the karyotype of case 2 was 46,XX,der(7)t(7;10)(p22;q25).ish(wcp7+;wcp 10+). The chromosomal abnormalities in case 1 resulted from a paternal balanced translocation while case 2 resulted from a maternal balanced translocation involving chromosomes 10 and 7 in both cases. The probands' phenotypes were correlated to the breakpoints and compared to previously reported cases with partial trisomy 10q. Both cases had the well characterized phenotype of the distal trisomy of 10q in the form of mental retardation, microcephaly, characteristic dysmorphic facies and limb anomalies as trisomy in both cases involved the 10q25-->qter region. However, case 1 with 10q23-->qter duplication showed more severe clinical manifestations than case 2 with less extensive 10q25-->qter trisomy. These included severe failure to thrive, cardiac involvement and death from respiratory and heart failure. This study confirmed that unbalanced chromosome regions of the long arm of chromosome 10 play an important role in developmental malformations and that a more severe form is associated with involvement of 10q23. It also emphasizes the importance of increasing public awareness regarding these chromosomal rearrangements and the importance of genetic counseling and prenatal diagnosis to avoid recurrences and associated family stress. This was clearly demonstrated in the second family in this study as the couple refused any follow up or further investigations due to religious beliefs despite their social and educational level.     

Interchange trisomy 21 by t(1;21)(p22;q22)mat

Interchange trisomy 21 by t(1:21)(p22:q22)mat: Interchange trisomy 21 by t(1;21)(p22;q22)mat was identified in a sporadic patient with Down syndrome. With a 21q22 specific probe, we observed signals on both normal 21 chromosomes and on the der. We reviewed the 23 published reports of families with reciprocal translocations leading to viable offspring with interchange trisomy 21. The breakpoints in chromosome 21 were mainly located in 21q (19/24 instances, including the present report) and in 19/23 cases the other chromosome involved in the translocation was (pairs 1-12). The underlying 3:1 segregation occurred mainly in carrier mothers; only one patient presented a de novo imbalance and in another case the father was the carrier. In addition, there were 4 instances of concurrence with another unbalanced segregation (adjacent-1 or tertiary trisomy) and 3 families with recurrence of interchange trisomy 21. The mean age of 14 female carriers at birth of interchange trisomy 21 offspring (24.8 yr) was lower that the mean (28.3 yr) found in a larger sample of mothers of unbalanced offspring due to 3:1 segregation (mostly tertiary trisomics) and was not increased with respect to the general population average. Overall, these data agree with previous estimates regarding recurrence risk (9-15%) and abortion rate (about 28%) in female carriers ascertained through an interchange trisomic 21 child.