Partial trisomy 9q- chromosomal syndrome

Summary The clinical features consisting mainly of enophthalmos, beaked nose, narrow palpebral fissures, receding chin, long fingers and toes, typical for chromosomal syndrome of partial trisomy 9q, were confirmed in a new case.     

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 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 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 21

Summary Cytogenetic analysis of a 6-year-old girl with moderate mental retardation revealed 46 chromosomes with a tandem translocation (21;21) resulting in a partial trisomy 21. Only the terminal band 21q22 was not in triplicate. G-, Q-, R-, and C-banding techniques and silver nitrate staining of the nucleolus organizer regions (NORs) were used to identify this chromosome fully.The phenotype of the patient was not typical for Down's syndrome, providing additional evidence that trisomy of band 21q22 is pathogenetic for the phenotype of Down's syndrome. This is also a new example in human pathology of a stable dicentric chromosome in which one of the centromeric constrictions appears to be nonfunctional.     

Partial trisomy 14q

Summary A dysmorphic female born with partial trisomy of the proximal segment of the long arm of chromosome 14 had 47 chromosomes. The extra one was acrocentric, smaller than the D group, and bigger than the G-chromosome group. By GTG banding it was identified as a deleted chromosome 14, the karyotype being 47,XX,+del 14(q24). Chromosome analysis of the parents was normal.     

Partial trisomy 10q

Summary Five cases from two nonrelated families with partial trisomy 10q due to a reciprocal translocation t(10;17)(q25;p13) and t(10;11)(q24;q23), respectively, are reported. The phenotypic findings are compared with those of 17 previously published cases; the clinical data justify the conclusion that cases with trisomy 10q show a specific syndrome of mental retardation and malformation characterized by psychomotor retardation, growth retardation, hypotonia, high forehead, flat face, fine and arched eyebrows, antimongoloid slant of the eyes, narrow palpebral fissures, hypertelorism, short nose, bowshaped mouth, short neck, (kypho)scoliosis, and in some cases microcephaly.     

Partial trisomy 6p

Summary A case of trisomy 6p216pter resulting from a maternal balanced t(2;6)(p25;p21) translocation is reported. The main clinical abnormalities were psychomotor retardation, hypotrophy, blepharophimosis, nystagmus, high nasal bridge, small mouth, sacral dimple, and systolic murmur. Other anomalies might have been due to partial 2p monosomy. Comparison with seven other cases of trisomy 6p allowed the delineation of a clinical entity. Direct proof of the localization of HLA genes was given by the presence of three haplotypes in the index patient.     

Partial trisomy 10p

Summary It is reported on a boy of 4 years 9 months with trisomy of the distal part of the short arm of a chromosome 10, due to a balanced 7/10 translocation in the father. Besides multiple minor dysmorphias the patient showed severe mental retardation, small stature, hypotonia, retarded bone age. The high and bulky forehead was especially remarkable, because this sign has also been noted in formerly reported cases with trisomy 10p.     

Partial trisomy 17q

Summary A 15-year-old deeply mentally retarded male is described with partial distal 17q trisomy (17q2217qter), as the result of a de novo 17q/21p translocation. Differential Ag-staining showed that the satellites of chromosome 21 were included in the translocation chromosome.     

Partial trisomy 3q

Summary A new case of partial trisomy 3q is reported in a 5-year-old female with severe congenital malformations and psychomotor retardation. A review of the literature, with a total of 11 patients, allows us to conclude that the clinical picture reminiscent of the Cornelia de Lange syndrome is caused by the trisomic state.     

Partial trisomy 4q.

Three new cases (one patient and two sibs) of partial trisomy 4q resulting from a parental translocation are reported. From the literature 22 cases are reviewed and the segregation risk of unbalanced and balanced translocations involving 4q chromosome is discussed.     

Trisomy 9q-. a variant of the 9p trisomy syndrome.

A low-birth-weight near-term male infant was found to have a non-familial 47,XY chromosome complement with an extra medium-sized metacentric chromosome slightly larger than a number 16. By Giemsa-trypsin (G-banding) this extra chromosome was determined to be a number 9 with deletion of approximately half of the long arm at region q 22. Chromosome studies on the clinically normal 38-year-old mother showed a balanced translocation with the deleted portion attached onto the distal end of a number 8 short arm, i.e. 46,XX,t(8;9)(p23;q22). Nondisjunction during meiosis of this woman's normal and deleted number 9 chromosomes is the basis of the child's abnormalities. One half-sibling of the child has a balanced translocation similar to that in the mother. Chromosome analyses on 4 others of the child's maternal half-siblings and on the maternal grandmother all showed normal patterns.     

Partial and complete trisomy 9: Delineation of a trisomy 9 syndrome

Summary Two infants with trisomy involving chromosome 9 are described. One had complete trisomy 9 and the other karyotype 47,XX,+der(9),t(7;9)(p22;q32)mat. A trisomy 9 syndrome is delineated, consisting of features of the trisomy 9p syndrome and various other malformations. These include abnormalities of the cardiovascular and urogenital systems, cranial suture anomalies, dislocation of the hips and knees and early death. A possible relationship of some of these findings to regions of 9q involved in cases of partial trisomy 9 is suggested.