Partial trisomy 6

A de novo 6q11-q15 duplication investigated by chromosome painting

A de novo interstitial duplication of the 6q11-q15 chromosome region, confirmed by the application of a chromosome 6 painting probe, was observed in a patient with craniofacial dysmorphism, psychomotor retardation, cryptorchidism and hypospadias. Despite the publication of several cases showing partial trisomy 6q, to our knowledge the duplication of the proximal region q11-q15 has not previously been reported.

Autosomal imbalance syndromes: genetic interactions and the origin of congenital malformations in aneuploidy syndromes

In some autosomal imbalance syndromes an additional imbalance interferes with the occurrence of the anomalies typical of the syndrome itself. For example, polydactyly was found in patients with "pure" del(3p) more frequently (11/23) than in patients where these deletions were associated with different partial trisomies (2/28). The opposite situation was shown in del(7q) syndrome where various defects of the holoprosencephalic group were found to be rarer in patients with "pure" deletions, than in cases with simultaneous occurrence of various partial trisomies. It suggests the importance of gene interaction in determining the phenotypic picture of autosomal imbalance syndromes.

Duplication (6q) syndrome diagnosed in utero

We report on a case of partial duplication 6q detected ultrasonographically. The clinical picture noted in utero is consistent with the adult phenotype previously reported in the literature.

Partial duplication of the long arm of chromosome 6: a clinically recognisable syndrome

Reciprocal translocations involving the short arm of acrocentric chromosomes can segregate to produce partial duplications without associated deletions. We present a case of an infant with a 46,XY,-15,+der(15),T(6;15)(q23;p12)pat chromosome complement. The infant had multiple congenital abnormalities including cranial anomalies, facial dysmorphism, anterior webbing of the neck, cardiac anomalies, and joint contractures. From a comparison of the infant's phenotype with 20 other patients with a similar duplication, it is evident that partial duplication of the long arm of chromosome 6 is a clinically diagnosable syndrome.

Partial trisomy 6q: case report with necropsy findings

A male infant with partial trisomy 6q is described. This patient shares features with 12 previously reported cases including hypertelorism, cleft soft palate, bow shaped mouth, micrognathia, short, laterally webbed neck, clubbing of hands and feet, syndactyly, and growth retardation. In addition, visceral anomalies less frequently reported are described. These observations may extend the phenotypic characterisation of the trisomy 6q syndrome.

Partial trisomy 6q and bilateral retinal detachment

An eight-year-old boy with trisomy 6q13----q21 is described with growth retardation, severe mental retardation, unusual facies, cleft palate, joint contractures and bilateral retinal detachment. To the authors' knowledge, this is the first case in which such an association has been recorded.

Interstitial deletion of the long arm of chromosome 6 [del(6) (q16q22)]: case report and review of the literature

Partial monosomy of 6q resulting from an interstitial deletion of bands q16----q22 was found in a 12-year-old boy manifesting mental retardation, seizure disorder, and dysmorphic features. The correlation of phenotypic expression and specific long arm deletions of chromosome No. 6 is discussed.

Duplication 6q24 leads to 6qter in an infant from a balanced paternal translocation

Duplication of 6q24 leads to 6qter was identified by GTG banding in an infant girl whose father was a balanced translocation carrier 46,XY,t(3;6)(p26 leads to q2402). At birth and at 4 mo she had proportionate short stature, microcephaly, asymmetric micrognathia, bow-shaped upper vermilion, long upper lip, submucous cleft palate, antimongoloid slant of palpebral fissures, telecanthus, prominent eyes, short neck with anterior and lateral webbing, short sternum, overlapping toes, wrist contractures, and hypertonicity. Later she was noted to have psychomotor retardation. Eleven previously published cases and our patient suggest that duplication of 6q (involving at least 6q25 leads to 6qter) produces a highly characteristic syndrome.

Trisomy 6qter

A previously reported patient with trisomy for the distal part of 6q was shown by R-banding to be trisomic for 6q26qter, due to a t(6;22)(q26;p12) mat. Altogether nine patients with 6qter trisomy have been reported. The main features of the 6qter trisomy syndrome are: severe mental and growth retardation; acrocephaly and brachycephaly; a carp-shaped mouth; micrognathia; a very short neck with unusual anterior webbing; joint contractures; the absence of severe inner organ malformations; and survival into adulthood.

A girl with an interstitial deletion of the short arm of chromosome 3 studied with a high-resolution banding technique

A girl with delayed growth in body height and weight, retarded psychomotor development, facial dysmorphism, high-arched palate, extension defects of elbows, and a probable hearing impairment is presented. A chromosome investigation by both conventional and high-resolution banding techniques revealed an apparently pure interstitial deletion of the proximal segment of the short arm of chromosome 3 (46,XX,del(3) (p11p14.2) de novo). The paternal karyotype is 47,XYY. The clinical features of the patient are compared with those of two previously reported cases in the literature with an interstitial 3p deletion.

Trisomy 6q25 leads to 6qter in two sisters resulting from maternal 6;11 translocation

Chromosome banding was used to define a partial duplication of the long arm of chromosome 6 (6q25 leads to 6qter) in two profoundly affected sisters and to identify their phenotypically normal mother and sister as balanced translocation carriers whose karyotypes were interpreted as 46,XX,t(6;11) (q25;q25). Prominent clinical features included profound mental retardation, hypertelorism, micrognathia, down-turned mouth, dental anomalies, clubfeet, webbed neck, late progressive scoliosis, flexion contractures, and low total finger ridge count. By comparison with published reports, it has been possible to establish a trisomy 6q25 leads to 6qter syndrome.