Cryptic duplication and deletion of 9q34.3 --> qter in a family with a t(9;22)(q34.3;p11.2)

A newborn male was referred for genetic evaluation because of multiple congenital abnormalities. Physical findings included a round face, telecanthus, hypertelorism, a short upturned nose with anteverted nares, small ears, micrognathia, short toes, and congenital heart disease. Chromosome analysis detected a possible deletion of 9qter because of satellite material on 9qter. Delineation by FISH and microarray CGH studies showed 46,XY,der(9)t(9;22)(q34.3;p11.2). The mother and maternal grandfather had a balanced t(9;22)(q34.3;p11.2) rearrangement. Also, the maternal great-aunt of the propositus was found to have a duplication of 9q34.3 --> qter. FISH was required to delineate her karyotype, which was 46,XX.ish der(22)t(9;22)(q34.3;p11.2). This maternal great-aunt and one of her daughters (cytogenetics not done) have a relatively normal phenotype, only reporting mild learning disabilities in school. Since the 22p material involved in this rearrangement is clinically irrelevant, this report describes an individual with a pure deletion of 9q34.3 --> qter and another with a pure duplication of 9q34.3 --> qter.     

Submicroscopic unbalanced translocation resulting in del10p/dup13q detected by subtelomere FISH

Chromosomal rearrangements involving the (sub)telomeres are an important cause of human genetic diseases: with the development of advanced molecular cytogenetic methods they have been identified as a major cause of mental retardation and/or congenital malformation syndromes. We identified a cryptic unbalanced de novo translocation 10p/13q by subtelomere FISH in a boy with mental and growth retardation (karyotype: 46,XY,der(10)t(10;13)(p15.1;q34)(D10S2488–,D13S296+)). Craniofacial dysmorphisms included frontal bossing, epicanthal folds, long philtrum, thin upper lip, short nose, mild retrognathy and a flat midface. In addition the patient had ASDII, a pyloric stenosis, bilateral inguinal hernias and cryptorchidism. His psychomotor development was significantly delayed. Microsatellite typing revealed the paternal origin of the two chromosomes involved in the rearrangement. By comparing our case with previously published patients with similar aberrations we conclude that the congenital malformations in our case are associated with the partial 10p deletion. The craniofacial features might be attributed to the 13q duplication. The identification of a 10p/13q translocation in our case highlights the importance of searching for cryptic subtelomeric imbalances in mentally retarded patients and helps to further delineate genotype–phenotype correlations in rare chromosomal disturbances.     

Duplication 19q13-qter and deletion 19p13-pter arising from an inversion (19)(p13.3q13.3) of maternal origin

Pericentric inversion of chromosome 19 appears to be a rare abnormality with only a few families reported. As far as we are aware, none of them were ascertained because of a recombinant individual. We describe the first identified case due to an affected patient, with duplication deficiency for chromosome 19 arising from a maternal inversion confirmed by FISH and CGH. His features included prenatal growth retardation, microcephaly, dysmorphic facies, congenital heart defect, hypoplasia of corpus callosum and psychomotor delay. The identification of recombinant individuals contribute to calculate a precise risk for inv (19) carriers and to provide a more accurate genetic counselling.     

9p deletion and distal 9q duplication due to a paternal pericentric inversion 9(p22q32)

A female infant with 46,XX,rec(9), dup q,inv(9)(p22q32)pat is presented. She had a duplication from 9q32 to qter and a deletion from 9p22 to 9pter. Phenotypical abnormalities observed corresponded with features noted in cases with distal dup (9q), while pathognomonic features of del(9p) syndrome were not observed.     

Infant with multiple congenital anomalies and deletion (9)(q34.3)

We report on a male infant with developmental delay, growth failure, hypotonia, dolichocephaly, hypoplastic midface, epicanthal folds, down-slanting palpebral fissures, foveal hypoplasia, tracheomalacia, pectus excavatum, supraventricular tachycardia, gut malrotation, hypospadias, talipes equinovarus, short third metatarsals, capillary hemangiomata, and a de novo terminal deletion at 9q34.3. © 1994 Wiley-Liss, Inc.     

Case with autistic syndrome and chromosome 22q13.3 deletion detected by FISH

Autism is a rare neurodevelopmental disorder with a strong genetic component. Co-occurrence of autism and chromosomal abnormalities is useful to localize candidate regions that may include gene(s) implicated in autism determinism. Several candidate chromosomal regions are known, but association of chromosome 22 abnormalities with autism is unusual. We report a child with autistic syndrome and a de novo 22q13.3 cryptic deletion detected by FISH. Previously described cases with 22q13.3 deletions shared characteristic developmental and speech delay, but autism was not specifically reported. This case emphasizes a new candidate region that may bear a gene involved in autism etiopathogenesis. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:839-844, 2000.     

FISH analysis in detecting 9p duplication (p22p24)

Authors report on a case of partial 9p duplication, involving the 9p22-9p24 region. This represents the second case of such duplication in which the breakpoints were precisely defined using fluorescence in situ hybridisation (FISH) with chromosome 9 specific painting and YAC DNA probes, localised onto 9p22-9p24 region. FISH analysis pinpointed chromosome breakpoints in dup(9)(p22p24) and excluded an insertion or a translocation from other chromosomes. The present report supports the segment 9p22-9p24 as the critical region for the observed phenotype of the duplication 9p syndrome.     

9p Deletion and distal 9q duplication due to a paternal pericentric inversion 9(p22q32)

A female infant with 46,XX,rec(9), dup q,inv(9)(p22q32)pat is presented. She had a duplication from 9q32 to qter and a deletion from 9q22 to 9pter. Phenotypical abnormalities observed corresponded with features noted in cases with distal dup (9q), while pathognomonic features of del(9p) syndrome were not observed.     

Identification of an unbalanced cryptic translocation t(9;17)(q34.3;p13.3) in a child with dysmorphic features

We report a case of an unbalanced cryptic telomeric translocation 46,XY,der(17),t(9;17)(q34.3;p13.3) in a boy with dysmorphic features and developmental delay. The proband had intrauterine growth retardation, postnatal short stature, and mild microcephaly. Magnetic resonance imaging showed incomplete myelination, but no evidence of lissencephaly. Cytogenetic analysis of the proband's peripheral blood showed an abnormal 17p. Fluorescence in situ hybridisation (FISH) with a Miller-Dieker cosmid probe did not detect a deletion for that area. Further analysis with a 17p telomere specific probe identified an unbalanced telomeric translocation. The same probe was used to determine the presence of an apparent balanced translocation t(9;17)(q34.3;p13.3) in the mother of the proband. The balanced translocation was confirmed with two cosmids that map distally on 9q34.3. Two phenotypically normal half sibs, a maternal aunt, a maternal uncle, and the maternal grandmother were found to be balanced translocation carriers as well. A subtle translocation carriers as well. A subtle translocation is one mechanism that can produce an abnormal phenotype in a patient who had a normal karyotype at lower band resolution levels.     

A report of a child with a deletion (9)(q34.3): a recognisable phenotype?

We report a case of a male infant who presented with congenital anomalies and was found to have a de novo deletion in the terminal region of the long arm of chromosome 9. He died at the age of 17 weeks of cardiorespiratory failure owing to RSV positive bronchiolitis. A review of previously published reports documented one previous report of a patient with a deletion of (9)(q34.3) and multiple congenital anomalies. Comparison with the previously reported case suggests that the phenotype observed constitutes a clinically recognisable pattern of malformations.     

A cryptic unbalanced translocation t(2;9)(p25.2;q34.3) causes the phenotype of 9q subtelomeric deletion syndrome and additional exophthalmos and joint contractures

We report on a 26-year-old woman with microcephaly, typical facial features of 9q subtelomeric deletion syndrome, exophthalmos, contractures of elbow and knee joints, severe muscular hypotonia, no ability to walk, and no speech development.Array CGH revealed a cryptic 9q34.3 deletion and 2p25.2-p25.3 duplication transmitted by her mother, who was carrying a balanced translocation of chromosomes 2p and 9q. There are about 50 reported cases of deletions of the subtelomeric part of chromosome 9q, however, duplications of only the terminal part of chromosome 2p are rare. Neuroblastoma, diaphragmatic hernia, neural tube defects, broncho-pulmonary abnormalities, and congenital heart defects are conditions associated with partial trisomy of larger fragments of 2p. To our knowledge there is only one case described with an isolated duplication as distal as in the patient reported here. Joint contractures and exophthalmos observed in this patient are also seen in our patient. These features are not allegeable by the deletion 9q34.3 identified in the patient reported here and may be a hint that terminal duplication of 2p could be associated with exophthalmos and contractures.     

Unbalanced cryptic 5p deletion/17p duplication identified by subtelomeric FISH in a family with a boy with chimerism and a balanced t(4;5)

The use of subtelomeric FISH probes has greatly supplemented conventional chromosome analysis in detecting cryptic anomalies in patients with mental retardation (MR), dysmorphic features, and congenital malformations. We report a 3-month-old boy who was diagnosed with ambiguous genitalia, dysmorphic features, and developmental delay. Standard chromosome studies on blood revealed a chimeric karyotype of 46,XY,t(4;5)(q31.1;q14)[46]/46,XX[4]. The boy had intra-abdominal gonads that were testicular in origin by biopsy. Multiple dysmorphic features, marked hypotonia, developmental delay, poor growth, and relative macrocephaly were noted on physical exam. His 2.5-year-old sister also presented with hypotonia, developmental delay, relative macrocephaly, and similar dysmorphic stigmata. In addition, she was diagnosed with several internal malformations. Her karyotype was 46,XX. Due to the striking phenotypic similarity, subtelomeric FISH studies were initiated in the siblings. In addition to the known balanced karyotypic abnormalities, the boy was found to have a derivative chromosome 5 with a 5pter deletion and a 17pter duplication. This cryptic abnormality was also detected in his sister. Chromosome analysis of the father revealed a subtle balanced t(5;17)(p15.31;p13.1) which was confirmed by subtelomeric FISH, whereas the mother's chromosome complement was normal. This familial constellation illustrates the usefulness of subtelomeric FISH in the diagnosis of cryptic chromosome abnormalities in patients for whom conventional karyotype does not disclose findings sufficient to explain the observed phenotypic anomalies.     

Maternal balanced translocation leading to partial duplication of 4q and partial deletion of 1p in a son: Cytogenetic and FISH studies using band-specific painting probes generated by chromosome microdissection

A 9-month-old boy with pre- and post-natal growth retardation, microcephaly, plagiocephaly, and several minor anomalies had the initial karyotype: 46,XY,der(1)t(1;?)(p36.1;?). Further analysis showed that the der(1) was derived from an unfavorable segregation of a maternal complex chromosome rearrangement, i.e., 46,XX,der(1)t(1;?)(p36.1;?), der(4)t(4;?)(q?;?). Whole chromosome fluorescence in situ hybridization (FISH) and chromosome microdissection were used to clarify the maternal karyotype as: 46,XX,der(1)t(1;4)(4qter→4q33::1p36.13→1qter),der(4)t(1;4)inv(4)(4pter→ 4q31.3::1p36.33→1p36.13::4q33→4q31.3::1p36.33→1pter). Therefore, the karyotype of the boy actually was 46,XY,der(1)t(1;4)(p36.13;q33). Clinical comparison of the patient's clinical findings showed similarities to individuals with partial del(1p) and dup(4q). To our knowledge the above cytogenetic abnormalities have not been described previously. This case further demonstrates the advantages of chromosome microdissection and FISH in the identification of anomalous chromosome regions and breakpoints. Am. J. Med. Genet. 71:160–166, 1997. © 1997 Wiley-Liss, Inc.     

A presumptive translocation 1p;2q resulting in duplication 1p and deletion 2q

Here we report on a girl with a translocation between 1 and 2 and duplication 1p and deletion 2q resulting in a multiple congenital anomaly syndrome including intrauterine growth retardation, microcephaly, hypotelorism, cleft palate, subglottic stenosis, umbilical hernia, scoliosis, anal atresia, bilateral calcaneovalgus, overlapping toes, and vertebral anomalies.