Microscopic neuroblastoma in a fetus with a de novo unbalanced translocation 3;10

We report on a fetus with a de novo unbalanced translocation 3;10 and a microscopic neuroblastoma. The fetus had the kary-otypic and phenotypic manifestations of partial dup (3q). The finding of a constitutional chromosomal abnormality and a microscopic neuroblastoma, although possibly coincidental, supports Knudson's two hit hypothesis for development of neuroblastomas and other embryonal tumors. In this case the first mutation is represented by the constitutional abnormality, possibly resulting in the microscopic neuroblastoma. A second mutation affecting the abnormal cells, which may be more prone to mutagenesis, may trigger a neuroblastoma. © 1994 Wiley-Liss, Inc.     

Sotos syndrome and de novo balanced autosomal translocation (t(3;6)(p21;p21))

In this report we describe a 6-year-old boy with Sotos syndrome and a de novo apparently balanced 3/6 translocation (karyotype: 46,XY,t(3;6)(p21;p21)). Pre- and postnatal overgrowth are observed in an increasing number of conditions of variable etiology. In the Sotos syndrome autosomal dominant inheritance with variable expression has been documented. Here we discuss the importance of the cytogenetic findings and postulate a relationship between the invisible loss of chromosomal material at 3p21 and/or 6p21 and the expression of the autosomal dominant gene.     

Partial trisomy 3q due to a de novo translocation t(X;3) (p21;q12)

A patient with several congenital malformations, principally in the face, cardiovascular system and genitalia, was found to have the karyotype 46 ,X,der(X),t,X;3)(Xqter← p21::3ql2-←3qter). A comparison of the clinical and cytogenetical findings with similar cases in the literature led to the conclusion that a partial trisomy 3q is the most likely cause for the symptoms in this patient.     

De novo balanced translocation (6;18)(q21;q21.3) in a patient with heterotaxia

We report on a sporadic case of heterotaxia with a de novo chromosome structural abnormality. The patient had inversely located heart (dextrocardia), stomach, duodenum, and cecum. In addition, she had cerebral atrophy, hypertelorism with telecanthus, infraorbital skin furrows, ear-lobe grooves, prominent maxilla and teeth, large carp mouth, short fifth fingers with limited flexion, generalized hypotonicity, and severe psychomotor retardation. High-resolution chromosome banding analysis demonstrated an apparently balanced translocation: 46,XX,t(6;18)(q21;q21.3). It is hypothesized that both heterotaxia and the chromosomal abnormality in the patient are causally related and a putative situs determining gene has been disrupted by the chromosome break, i.e., a position effect or a cryptic deletion at around the breakpoints. The translocation in our patient may be a good source for positional cloning of the gene. © 1996 Wiley-Liss, Inc.     

A de novo translocation, 14q21q,with a microchromosome—14p21p

A familial translocation, t(14;21)(14p21p;14q21q), in a mother and her child is described. The translocation was ascertained through the birth of a Down syndrome baby with the chromosome constitution 47,XX,-14, +der 14, +der 21,t(14;21)(q11; p12) mat. A 1:3 segregation in the maternal meiosis is suggested for the evolution of the unbalanced chromosome state. The main translocated chromosome 14q21q mimics the product of a Robertsonian translocation, while the 14p21p chromosome has the morphology of a satellited microchromosome. The cytogenetic nature of this translocation is discussed.     

A de novo translocation t(3;17)(q26.3;q23.1) in a child with Cornelia de Lange syndrome.

A female infant with Cornelia de Lange syndrome and severe limb reduction defects is described. Chromosome analysis showed a de novo translocation with breakpoints at 3q26.3 and 17q23.1. This is the first reported case of a de novo translocation associated with this syndrome.     

Tentative assignment of gene for oto-palato-digital syndrome to distal Xq (Xq26–q28)

Detailed physical mapping of oto-palato-digital (OPD) syndrome gene on the X-chromosome was attempted on a family of 3 generations with 2 affected men. Although the result remains statistically non-significant, it indicates that the OPD-I gene might be located on the distal Xq.     

Melkersson-Rosenthal syndrome and de novo autosomal t(9;21)(p11;p11) translocation

In this report we describe a 26-year-old female with the typical clinical symptoms and signs of Melkersson-Rosenthal syndrome, an autosomal dominant disorder with variable expression, and a de novo t(9;21)(p11;p11), and suggest that the "Melkersson-Rosenthal gene" is located at 9p11.     

A de novo tandem duplication 15(q21→qter) mosaic

A Yugoslav family with one female and three male children with Robert's syndrome (RS) is described. To our knowledge, there is no other family with four siblings presenting this genopathy. Most of the symptoms of the fourth sibling were identical to those found in the SC syndrome, suggesting the same genetic origin. The same chromosomal changes which were discovered in the third sibling were also found in the fourth sibling. These chromosomal abnormalities could prove useful for antenatal diagnosis.     

Inversion (X)(p11.4q22) associated with Norrie disease in a four generation family

We report on a 4-generation family in which Norrie disease occurs together with a pericentric inversion of the X chromosome in all affected males and carrier females. The breakpoint in the short arm of the X chromosome appears to be at the purported location of the Norrie disease gene. This is the second report of an association between Norrie disease and a chromosome aberration involving Xp11, and the first report of a specific gene disruption, thus physical gene location, due to a pericentric chromosome inversion. © 1993 Wiley-Liss, Inc.     

Derivative (1;18)(q10;q10): a recurrent and novel unbalanced translocation involving 1q in myeloid disorders.

We report two cases of hematological malignancies, comprising a case of myelodysplastic syndrome (MDS) that rapidly evolved into acute myeloid leukemia, and a case of myeloproliferative disorder (MPD), in which der(1;18)(q10;q10) was found as the sole acquired karyotypic abnormality. This observation indicates that the unbalanced translocation is a recurrent aberration in myeloid disorders. To the best of our knowledge, centromeric fusion between long arms of chromosomes 1 and 18, leading to a normal chromosome 18 substituted with a der(1;18) chromosome, is novel and has not been described in cancer. Mechanistically, either trisomy 1q or monosomy 18p that results from the translocation may potentially contribute to leukemogenesis. Finally, chromosomes with large constitutive heterochromatin bands such as chromosome 1 may be at risk of centromeric instability and be predisposed to centromeric fusion with other chromosomes.     

A malignant triton tumor with an unbalanced translocation (1;13)(q10;q10) and an isochromosome (8)(q10) as the sole karyotypic abnormalities

The karyotype of a malignant nerve sheath tumor with rhabdomyosarcomatous differentiation (malignant triton tumor) of a 58-year-old woman is reported. The tumor revealed an isochromosome for the long arm of chromosome 8 and an unbalanced translocation (1;13)(q10;q10) leading to a gain of the long arm of chromosome 1 as the sole karyotypic abnormalities.     

A translocation (7;10)(q35;q21) in a differentiated papillary carcinoma of the thyroid

A case of differentiated thyroid carcinoma is reported. Cell culture techniques and cytogenetic investigations are described. A t(7;10)(q35;q21) appears to be the sole chromosome abnormality.     

Opitz trigonocephaly C syndrome in a boy with a de novo balanced reciprocal translocation t(3;18)(q13.13;q12.1)

Opitz trigonocephaly C syndrome (OTCS) is a multiple congenital anomaly syndrome characterized by trigonocephaly, mental retardation, a typical facial appearance, redundant skin, joint and limb abnormalities, and visceral anomalies. We describe a patient with the manifestations of OTCS who also had a de novo balanced reciprocal translocation t(3;18)(q13.13q12.1). His phenotype is a mild form with mild developmental delay and no severe visceral anomalies. Our findings suggest the possible existence of a new locus responsible for OTCS either on 3q13.13 or 18q12.1.     

Rubinstein‐Taybi syndrome caused by a de novo reciprocal translocation t(2;16)(q36.3;p13.3)

Rubinstein‐Taybi syndrome (RTS) is a multiple congenital anomalies and mental retardation syndrome characterized by facial abnormalities, broad thumbs, and broad big toes. We have shown previously that disruption of the human CREB‐binding protein (CBP) gene, either by gross chromosomal rearrangements or by point mutations, leads to RTS. Translocations and inversions involving chromosome band 16p13.3 form the minority of CBP mutations, whereas microdeletions occur more frequently (∼10%). Breakpoints of six translocations and inversions in RTS patients described thus far were found clustered in a 13‐kb intronic region at the 5′ end of the CBP gene and could theoretically only result in proteins containing the extreme N‐terminal region of CBP. In contrast, in one patient with a translocation t(2;16)(q36.3;p13.3) we show by using fiber FISH and Southern blot analysis that the chromosome 16 breakpoint lies about 100 kb downstream of this breakpoint cluster. In this patient, Western blot analysis of extracts prepared from lymphoblasts showed both a normal and an abnormal shorter protein lacking the C‐terminal domain, indicating expression of both the normal and the mutant allele. The results suggest that the loss of C‐terminal domains of CBP is sufficient to cause RTS. Furthermore, these data indicate the potential utility of Western blot analysis as an inexpensive and fast approach for screening RTS mutations. Am. J. Med. Genet. 92:47–52, 2000. © 2000 Wiley‐Liss, Inc.     

Congenital arhinia with de novo reciprocal translocation, t(3;12)(q13.2;p11.2)

A female newborn suffering from congenital arhinia with complete airway obstruction is reported. In addition, she had hypertelorism, microphthalmia, high-arched palate, and hypoplasia of the auditory canal and mastoid and facial bones, along with the absence of olfactory bulbs and tracts. She had a de novo reciprocal translocation between chromosomes 3q13.2 and 12p11.2. Certain gene(s) located at either of the breakpoints, 3q13.2 and 12p11.2, may be involved in the pathogenesis of her arhinia.