Complex familial rearrangement of chromosome 9p24.3 detected by FISH

We describe a newborn male with minor facial anomalies, pyloric stenosis, and a chromosome rearrangement that involves deletion and addition of material at 9p24.3. Routine studies showed a 46, XY, add (9) (p24) karyotype. Fluorescence in situ hybridization (FISH) with two different whole chromosome probes for chromosome 9 failed to identify whether the additional material was derived from that chromosome. FISH with single copy YAC probes from 9p24 (D9S1858, D9S1813 and D9S54) showed a more complex rearrangement involving a deletion at D9S1858 but not at D9S1813 or D9S54. Parental chromosome studies demonstrated an apparently identical 9p abnormality in the patient's mother. This report describes a familial chromosome rearrangement in an abnormal child and his normal mother and demonstrates the use and limitations of FISH in characterizing chromosomal abnormalities. Am. J. Med. Genet. 76:306–309, 1998. © 1998 Wiley-Liss, Inc.     

Interstitial de novo deletion of the long arm of chromosome 5: Mapping of 5q bands associated with particular malformations

A new case of interstitial deletion of the long arm of one chromosome No. 5 (q13→q22) is described. The girl shows mental retardation, severe hypotonia, dysmorphic facies and peculiar dermatoglyphics. The relationship between partial trisomies and partial monosomies of 5q chromosomal segments and associated clinical features is discussed. It seems possible to draw a rough phenotypic map of the long arm of chromosome 5 (5q), correlating observed malformations and phenotypic features with specific chromosomal regions.     

Partial monosomy 5p and partial trisomy 5q due to paternal pericentric inversion of chromosome 5

Summary A male infant with partial monosomy 5p and partial trisomy 5q due to paternal pericentric inversion of chromosome 5 (46,XY,rec(5), dup q,inv(5)(p15.1q35.1)pat) is reported together with the oral findings. The phenotype was chiefly the cri-du-chat syndrome. Severe retardation of mental and motor development, microencephaly, cardiac malformation, crying and facial appearance unique to the cri-du-chat syndrome were observed. Perioral and intraoral findings included thin upper lip, downturning corners of mouth, micrognathia, shallow palate, and cleft of soft palate. Anterior deciduous teeth were small and canine deciduous teeth were conic. The row of deciduous teeth showed a flat arch-like shape that was very wide but short in length. No abnormality was noted in the number of deciduous teeth or the timing of eruption.     

Kallmann syndrome associated with complex chromosome rearrangement

We report on a male with Kallmann syndrome (KS) and an apparently balanced complex chromosome rearrangement (CCR): 46,XY,t(3;9)(9;12)(q13.2;q21.2p13;q15). This is the first known report of a CCR in the KS and the second reported case of a definitive autosomal chromosome abnormality with KS. Possible relationships between the cytogenetic abnormality and KS are discussed. © 1993 Wiley-Liss, Inc.     

Partial monosomy of chromosome 1p36.3: Characterization of the critical region and delineation of a syndrome

We describe 5 patients ranging in age from 3 to 47 years, with karyotypic abnormalities resulting in monosomy for portion of 1p36.3, microcephaly, mental retardation, prominent forehead, deep-set eyes, depressed nasal bridge, flat midface, relative prognathism, and abnormal ears. Four patients have small hands and feet. All exhibited selfabusive behavior. Additional findings in some of the patients include brain anomalies, optic atrophy, hearing loss and skeletal deformities. The breakpoints within chromosome 1 were designated at 1p36.31 (3 cases), 1p36.32 (1 case) and 1p36.33 (1 case), Thus, the smallest region of deletion overlap is 1p36.33→1pter. Detection of the abnormal 1 relied on high resolution G-band analysis. Fluorescence in situ hybridization (FISH) utilizing a DNA probe (Oncor D1Z2) containing the repetitive sequences in distal 1p36, confirmed a deletion of one 1 homologue in all 5 cases. The abnormal 1 resulted from a de novo deletion in only one patient. The remaining patients were either confirmed (3 cases) or suspected (1 case) to have unbalanced translocations. Despite the additional genetic imbalance present in these four cases, monosomy of 1p36.33 appears to be responsible for a specific clinical phenotype. Characterization of this phenotype should assist in the clinical diagnosis of this chromosome abnormality. © 1995 Wiley-Liss, Inc.     

Two children with de novo del(9p)

We describe two patients with characteristic manifestations of the del(9p) syndrome. Among the prominent manifestation are moderate mental retardation, trigonocephaly, flat nasal bridge, anteverted nostrils, long philtrum, square and hyperconvex nails, and apparently long digits. The metacarpophalangeal pattern profiles of the patients showed that the clinical impresion of long fingers may be due to relative shortness of the metacarpals rather than to elongation of the phalanges.     

Direct duplication of 9p22→p24 in a child with duplication 9p syndrome

A de novo direct duplication of 9p22→p24 was shown in a child with a duplication 9p phenotype by GTG banding and fluorescence in situ hybridization (FISH) using a chromosome-9 specific painting probe as well as 6 YAC DNA probes localized to the 9p13–9p23 region. The breakpoints in this patient and previously reported patients suggest that 9p22 may be the critical region for duplication 9p syndrome. Am. J. Med. Genet. 77:268–271, 1998. © 1998 Wiley-Liss, Inc.     

Maternal origin of a unique extra chromosome,der(9)(pter→q13::q13→q12:) in a girl with typical trisomy 9p syndrome

We report on a girl with the typical trisomy 9p syndrome who had an additional E‐sized metacentric chromosome. On the basis of GTG‐ and CBG‐banding, her karyotype was considered to be 47,XX,+der(9)(pter→q13::q13→q12:) de novo. Results of a fluorescence in situ hybridization study using a chromosome 9‐specific painting probe were compatible with this cytogenetic interpretation. Molecular analyses of six highly polymorphic dinucleotide repeat loci on the short arm and the proximal long arm of chromosome 9 demonstrated that the girl inherited one allele from her father and two identical or different alleles from the mother. We speculated that the extra chromosome may have resulted from either nondisjunction of chromosome 9 followed by a U‐type exchange and a crossing‐over between different sister chromatids during maternal meiosis I and subsequent breakage and malsegregation during meiosis II, or nondisjunction during meiosis II followed by isochromosome formation in one of the two maternal chromosomes 9 and subsequent breakage. © 2001 Wiley‐Liss, Inc.     

Beckwith-Wiedemann syndrome due to 11p15.5 paternal duplication associated with Klinefelter syndrome and a "de novo" pericentric inversion of chromosome Y

We report on an infant who had been prenatally diagnosed with Klinefelter syndrome associated with a "de novo" pericentric inversion of the Y chromosome. A re-evaluation at 3 years of age suggested that he was also affected by Beckwith-Wiedemann syndrome (BWS). Karyotype was repeated and fluorescence in situ hybridisation (FISH) analysis revealed trisomy for 11p15.5-->11pter and a distal monosomy 18q (18q23-->qter). Parental cytogenetic studies showed that the father carried a balanced cryptic translocation between chromosomes 11p and 18q. Furthermore, the child had an extra X chromosome and a "de novo" structural abnormality of chromosome Y. Thus, his karyotype was 47,XX, inv (Y) (p11.2 q11.23), der(18) t (11;18) (p15.5;q23) pat. ish der(18) (D11S2071+, D18S1390-). Two markers on the X chromosome showed that the extra X of the child was paternally inherited. No deletions were observed on the structurally abnormal Y chromosome from any of the microsatellites studied. Clinical findings of patients with BWS due to partial trisomy 11p reveal that there is a distinct pattern of dysmorphic features associated with an increased incidence of mental retardation when comparing patients with normal chromosomes. This fact reinforces that FISH study have to be performed in all BWS patients, specially in those with mental retardation since small rearrangements cannot be detected by conventional cytogenetic techniques.     

A case of de novo interstitial deletion of chromosome 9(p12p13)

The present paper describes a girl with a small de novo deletion of chromosome 9(p12p13). This deletion has not been published previously. The deleted fragment is clearly outside the region involved in the so-called deletion 9p syndrome. The patient had mild dysmorphic features and feeding problems during the first weeks of life, but is now developing well. Because of the lack of severe clinical features in this patient, we speculate that the deletion may be prevalent in other patients who have no clinical indication for chromosome investigation.     

Prenatal diagnosis of a de novo trisomy 6q22.2→6qter and monosomy lpter→1p36.3. Case report with a 2-year follow-up and a brief review of other prenatal cases of partial trisomy 6q

We report a de novo trisomy 6q22.2→6qter and monosomy lpter→1p36.3 identified in amniocytes by GTG banding and FISH. While ultrasonography demonstrated malformations that did not suggest a specific chromosomal syndrome, a male infant with features consistent with trisomy 6q was born. He was followed up until 23 months, when he died after cardiac surgery. The only two other prenatal cases of trisomy 6q were compared with our patient. A literature review showed that trisomy 6q has not been reported in association with the anomalies seen by ultrasound in this case.     

A pericentric inversion of chromosome 9 and a rearrangement involving chromosomes 9 and 10, observed in two generations. Clinical description of chromosome 9 (p12-p21) deletion syndrome

The clinical picture associated with a deletion of a central part of the short arm of chromosome no. 9 is described in two siblings. The clinical signs differ from those described in deletion of the terminal part of the short arm. Pericentric inversion of chromosome no. 9, combined with a rearrangement involving chromosomes 9 and 10, was found in the mother and the maternal grandmother of the propositus.     

Two patients with overlapping de novo duplications of the long arm of chromosome 9, including one case with Di George sequence

Duplications of chromosome 9q are rare. We describe the cytogenetic and phenotypic findings in 2 patients, one with a large duplication covering most of 9q (q12–q33.2) and one with a smaller duplication (q21.12–q22.1) who had Di George sequence (DGS). The chromosome 9 origin of the extra material in the second case was confirmed by fluorescence in situ hybridization (FISH) analysis with a whole chromosome 9 paint. Microdeletions of chromosome 22 are common in DGS and have been reported in CHARGE association. This is the first report of an association of a chromosome 9 abnormality with DGS in the absence of a chromosome 22 abnormality and the seventh report of a patient with a duplication of a large portion of 9q (q11–q13 to q32–q33). © 1994 Wiley-Liss, Inc.     

De novo t(4;5) (q3100; q2200) with del(5)(q1500q2200). Tentative delineation of a 5q monosomy syndrome and assignment of the critical segment

An 8-month-old boy with multiple malformations and psychomotor retardation was found to have a de novo t(4;5)(q1300;q2200) with del(5)(q1500q2200). The phenotypical comparison with 10 similar monosomic cases from the literature led us to tentatively delineate a 5q monosomy syndrome and to postulate the band 5q15 as the correspondent critical segment.     

A case of de novo i(12p) with 12q whole-arm translocation mosaicism

We report a dup(12p) due to a de novo i(12p) in a girl with mosaicism for 12q whole-arm translocations onto 7p, 7q, and 11q terminal regions. The dup(12p) syndrome was confirmed by clinical, cytogenetic, and LDH-dosage studies.     

EEC syndrome (ectrodactyly, ectodermal dysplasia and cleft lip/palate) with a balanced reciprocal translocation between 7q11.21 and 9p12 (or 7p11.2 and 9q12) in three generations

Familial cases (a grandfather, a father and a daughter) of the EEC syndrome (ectrodactyly, ectodermal dysplasia and cleft lip/palate) are reported. All of them have a balanced reciprocal translocation (46,XY or XX, t(7;9) (q11.21;p12) or (46,XY or XX, t(7;9) (p11.2;q12)), but no other members of the family have either the EEC syndrome or chromosome abnormalities. This indicates that one of the chromosome sites 7q11.21, 9p12, 7p11.2 and 9q12 is a candidate for gene locus of the EEC syndrome.     

Familial Wolf's syndrome with a hidden 4p deletion by translocation of an 8p segment. Unbalanced inheritance from a maternal translocation (4;8)(p15.3;p22). Case report, review and risk estimates

This is the case report of a patient with Wolfs syndrome having a monosomy 4pter→p15.3 and an additional trisomy 8pter→p22, derived from a maternal balanced translocation t(4;8)(p15.3;p22) after 2:2 disjunction and adjacent-1 segregation. The patient's phenotype is presumably slightly modified by the trisomic 8p segment. Literature analyses indicate that phenotypic "hybrids" with traits of monosomy 4p and of other autosomal segment trisomies exist.
The dermatoglyphics of the patient were not highly characteristic for Wolfs syndrome. Also the dermatoglyphics of the balanced translocation carriers were unspecific and did not reflect the carrier status. Pedigree analyses of 46 reported families with reciprocal translocations involving the short arm of chromosome 4 show a high risk (20.5%±4.6%) for unbalanced offspring (trisomy or monosomy 4p) after 2:2 disjunction and adjacent-1 segregation, if the breakpoint in the recipient chromosome is terminal and the resulting imbalance concerns the 4p segment only. It is considerably lower (4.5%±2.5%) if the breakpoint in the recipient chromosome is subterminal, as in the reported case, and the resulting imbalance concerns other chromosome segments additionally to the 4p segment. In both instances, the risk decreases with increasing segment length. The risk for unidentified abortions, stillbirths or neonatal deaths is also high in these families (about 40%). The frequency of progeny with balanced compared to progeny with normal karyotype corresponds to the expected 50% for alternate segregation.     

20‐Mb duplication of chromosome 9p in a girl with minimal physical findings and normal IQ: Narrowing of the 9p duplication critical region to 6 Mb

We studied the case of a girl with a partial 9p duplication, dup(9)(p22.1 → p13.1). Molecular cytogenetics studies defined the chromosome 9 rearrangement as a direct duplication of 20 Mb from D9S1213 to D9S52. Microsatellite analysis demonstrated the presence of a double dosage of the paternal alleles and demonstrated that the duplication occurred between sister chromatids. The patient's phenotype was almost normal, with a few minor anomalies (dolichocephaly, crowded teeth, high arched palate) and normal IQ. The breakpoint's location in this patient and previously reported cases suggest that the critical region for the 9p duplication syndrome lies within a 6‐Mb portion of chromosome 9p22 between markers D9S267 and D9S1213. © 2002 Wiley‐Liss, Inc.