A duplication dup(4)(q28q35.2) de novo in a newborn

We report here a case of a newborn with hypotrophy and somatic stigmatization: microcephaly, facial dysmorphism, heart defect and immunodeficiency syndrome. The proband's karyotype was 46,XY,dup(4)(q28q35.2) de novo with chromosomal breaks in 4% of metaphases. We demonstrate the usefulness of a combination of physical examination, classical cytogenetics, FISH and PCR techniques in order to establish correct diagnosis because of overlap of some clinical and cytogenetic features of Nijmegen breakage syndrome (NBS) and duplication 4q in our patient. Although FISH technique detected translocation t(14q;21q) in 4 metaphases, deletion 657del5 in exon 6 of the NBS1 gene associated with NBS in Slavic population was not confirmed. We compare in this report similarity of the clinical picture of our patient, NBS cases and other patients carrying a duplication of the distal part of 4q as described in the literature.     

De novo balanced translocation (2;10)(q24;q22) associated with mental retardation

We report a case of a reciprocal translocation between the long arms of the 2 and 10 chromosomes observed in a 14-year-old male with mild mental impairment, compulsive and obsessive behavior. The apparently balanced translocation was characterized by fluorescence in situ hybridization and the karyotype was 46, XY, t(2;10)(q24;q22). The way by balanced chromosomal translocations can lead to a disease phenotype are reviewed and discussed.     

De novo dir dup (1)(q3200----4200) in an adult. Further delineation of the pure 1q trisomy syndrome

An adult male patient with a "de novo" pure trisomy 1q32---q42 was studied. Literature review of 33 cases with 1q trisomy allowed singling out a distinctive phenotype by eliminating clinical features of concomitant aneusomies. It is concluded, however, that the clinical pictures of the "pure" and "impure" 1q trisomies are similar and that the critical segment includes bands q32 and q41.     

Partial duplication of the short arm of chromosome 2 (dup(2)(p13----p21) associated with mental retardation and an Aarskog-like phenotype

In this report we describe a 3-year-old boy with partial trisomy of the short arm of chromosome 2 due to a de novo tandem duplication 2(dup(2)(p13----p21)). In addition to severe growth retardation and moderate psychomotor delay he presented a dysmorphic syndrome compatible with the clinical diagnostic of Aarskog syndrome.     

A new case of reciprocal translocation in a young bull: rcp(11;21)(q28;q12)

Routine cytogenetic investigations of the Chianina cattle (BTA) breed revealed the presence of longer and smaller chromosomes than the largest (BTA1) and smallest (BTA29) chromosomes in the cells of a young, normal-looking bull used for reproduction. Application of both RBA-banding and Ag-NOR techniques, as well as the use of the FISH technique and specific molecular markers of both BTA11 (IL1B, ASS and LGB) and BTA21 (SERPINA and D21S45) established that these two abnormal chromosomes were the product of a reciprocal translocation between BTA11 and BTA21. Both der(11) and der(21) were C-band positive and the chromosome regions affected were rcp(11;21)(q28;q12). The young bull had a normal body conformation, including external genitalia, normal levels of testosterone (as in the control) and non-detectable levels of both 17 beta-estradiol and progesterone (as in the control). The animal never showed libido in the presence of both males and females in oestrus. After slaughter at 18 months, histological evaluation revealed normal organized testes, seminiferous tubules and epididymis but with poor proliferative germ cells consisting mainly of spermatogonia, middle pachytene spermatocytes and early spermatids with late spermatids and spermatozoa being very rare.     

Microduplications in 22q11.2 and 8q22.1 associated with mild mental retardation and generalized overgrowth

The 22q11.2 microduplication is a genomic disorder, characterized from a variable phenotype ranging from different defects to normality. The most common microduplication of 22q11.2 is 3 Mb in size, but there are also cases reported with atypical duplications between 0.8 Mb and 6 Mb.     

PLAG1 activation in lipoblastoma coinciding with low-level amplification of a derivative chromosome 8 with a deletion del(8)(q13q21.2)

Lipoblastoma is a benign uncommon soft-tissue-tumor resembling fetal adipose tissue affecting mainly children under three years of age. In lipoblastoma, the typical cytogenetic changes are clonal rearrangements involving chromosomal region 8q11-->q13. The oncogene PLAG1 (pleomorphic adenoma gene 1) is located within this chromosomal region on band 8q12. Recent reports have demonstrated that in lipoblastoma, the PLAG1 gene is activated by 'promoter-swapping'. Herein, we demonstrate that in lipoblastoma, the PLAG1 gene may also be activated by low-level amplification. We report on a lipoblastoma with the karyotype 48 approximately 50,XX,del(8)(q13q21.2),+del(8)(q13q21.2)x4[cp12]. Subsequent FISH analysis on uncultured tumor cells confirmed this result and demonstrated a low-level amplification of the chromosomal region 8pter-->8q13 and 8q21.2-->8qter. A partial monosomy was seen for the chromosomal region 8q13-->8q21.2. No other gains or losses were observed by CGH analysis. RT-PCR analysis showed that the PLAG1 gene is activated in the tumor sample of the lipoblastoma analyzed, in contrast to normal fatty tissue without PLAG1 expression. In conclusion, our results demonstrate that low-level amplification is a further mechanism of PLAG1 activation in lipoblastomas.     

Dissection of an inverted X(p21.3q27.1) chromosome associated with mental retardation

In a 6 year old boy referred for mental retardation, fragile X syndrome was ruled out by cytogenetic and molecular analyses. Cytogenetic investigations revealed an inverted X chromosome (p21.3q27.1). A similar chromosomal rearrangement was detected in his mildly mentally retarded mother. Fluorescence in situ hybridization (FISH), using a panel of ordered YAC clones, allowed the identification of YACs spanning both the Xp21.3 and Xq27.1 breakpoints, where many non-specific mental retardation loci have been reported so far. Further investigations by FISH showed that the IL1RAPL1 gene at Xp21.3 was disrupted by the X chromosome inversion and therefore its inactivation may be related to the mental retardation observed in our patients.     

Siblings with opposite chromosome constitutions,dup(2q)/del(7q) and del(2q)/dup(7q)

Chromosome 7q36 microdeletion syndrome is a rare genomic disorder characterized by underdevelopment of the brain, microcephaly, anomalies of the sex organs, and language problems. Developmental delay, intellectual disability, autistic spectrum disorders, BDMR syndrome, and unusual facial morphology are the key features of the chromosome 2q37 microdeletion syndrome. A genetic screening for two brothers with global developmental delay using high-resolution chromosomal analysis and subtelomeric multiplex ligation-dependent probe amplification revealed subtelomeric rearrangements on the same sites of 2q37.2 and 7q35, with reversed deletion and duplication. Both of them showed dysmorphic facial features, severe disability of physical and intellectual development, and abnormal genitalia with differential abnormalities in their phenotypes. The family did not have abnormal genetic phenotypes. According to the genetic analysis of their parents, adjacent-1 segregation from their mother's was suggested as a mechanism of their gene mutation. By comparing the phenotypes of our patients with previous reports on similar patients, we tried to obtain the information of related genes and their chromosomal locations.     

A new case of reciprocal translocation t(10;13)(q16;q21) diagnosed in an AI boar

A new case of reciprocal translocation t(10;13)(q16;q21) was detected in a hybrid boar (Large White x Pietrain x Duroc x Hampshire) from an artificial insemination (AI) station. Altogether, 258 sires of 4 pure breeds as well as hybrid lines and crossbreeds were investigated. The diagnosis was based on classical cytogenetic examination following the standard protocols of lymphocyte cultures, Giemsa staining and G-, C- and Ag-I banding techniques. The population screening performed was an initial part of a long-term karyotype control system of boars kept at AI stations, which was started by the National Research Institute of Animal Production in Poland in 2007.     

Interstitial dup(1p) and severe intrauterine growth retardation

An 1,860 g baby girl was born spontaneously after a 38 weeks pregnancy with important foetal hypotrophy and died at 6 weeks of life. She had an inverted duplication of a small part of the short arm of chromosome 1p:46, XX, inv dup(1) (pter p31::p11p13::p31 ter). This observation is compared to three others reported in the literature with intrachromosomal duplication of 1p.     

Duplication dup(1)(q41q44) defined by fluorescence in situ hybridization: delineation of the 'trisomy 1q42-->qter syndrome'

We report on a novel case of pure partial tandem duplication 1q42q43 confirmed by fluorescence in situ hybridization (FISH). We compare the manifestations of our patient with similar cases previously reported. We conclude that the most common clinical manifestations of trisomy 1q42qter are prenatal and postnatal growth retardation, relative macrocephaly, triangular face, prominent forehead, broad nasal bridge, abnormal philtrum, micro/retrognathia, cardiac defects and mental retardation. We would like to emphasize the importance of the FISH technique in the identification of the duplicated segment.     

Moderate mental retardation and mild dysmorphic syndrome in proximal 7q interstitial deletion

In this report we describe a proximal 7q interstitial deletion in a 3-years-old moderately mentally retarded girl with mild dysmorphic features but absence of severe malformations.     

A 3p deletion syndrome in a child with both del(3)(p25-->pter) and dup(17)(q23-->qter).

A child with monosomy for the distal part of the short arm of chromosome 3 (3p25-->pter) and trisomy for the terminal portion of the long arm of chromosome 17 (17q23-->qter) is presented. This unbalanced karyotype was derived from a balanced reciprocal 3p/17q translocation in the phenotypically normal mother. Main clinical features in the proband included growth and mental retardation, hypotonia, hirsutism, micro/brachycephaly, triangular face, synophris, broad and full nose, long philtrum, narrow upper lip, low set, posteriorly turned ears, anteriorly placed anus and congenital heart defect (Tetralogy of Fallot). Most of these clinical manifestations have been constantly reported in previous cases with terminal 3p deletion.     

A case of chronic myeloid leukemia with a translocation (12;22)(p13;q11)

Summary Chromosomal studies of the bone marrow and cultured peripheral blood cells in a 42-year-old female with the clinical and laboratory features typical for CML revealed a previously undescribed variant translocation involving chromosomes 12 and 22.     

Fragile (X) X-linked mental retardation. II. Frequency and replication pattern of fragile (X)(q28) in heterozygotes

The frequency of cytologic expression and the replication pattern of the fragile (X) [fra(X)] were investigated in 28 fra(X) heterozygotes, of which 25 agreed to psychological assessment. One-third of the heterozygotes in this study are mentally retarded. The intellectually impaired carriers had a higher frequency of fra(X) and a higher proportion of early-replicating fra(X) than the normally intelligent carriers. The early-replicating fra(X) accounted for 39% of the variability in IQ and the late-replicating fra(X) for 12%. Age had a minimal inverse effect on fra(X) expression and replication pattern. Thus, it appears that mental retardation in females heterozygous for the fra(X) may largely be a function of the proportion of cells with an early-replicating, active X chromosome possessing the fragile site.     

A second case of inv(4)pat with both recombinants in the offspring: rec dup(4q) in a girl with Wolf-Hirschhorn syndrome and rec dup(4p)

In a girl presenting with features of Wolf-Hirschhorn syndrome, cytogenetic and molecular cytogenetic analysis revealed a rearranged chromosome 4 with monosomy of the distal bands 4pter-->4p16.2 and trisomy of the distal bands 4q35.1-->4qter [rec dup(4q)] due to a large, paternal pericentric inversion. In the following two pregnancies, prenatal diagnosis showed the same imbalance in one fetus and a reverse segmental imbalance [rec dup(4p)] in the other. We discuss the recombination risk of the given inversion with respect to the size of the inverted segment and the viability of the recombinants. The high frequency of recombinants in this family and others suggests a high recurrence risk in similar cases with large pericentric inversions comprising almost entire chromosomes.     

Complex translocation t(9;21)(9;22)(q12p13)(q12q11) in the family of a child with 9p trisomy syndrome

Summary Leukocyte peroxidase activity was estimated in 5 patients with the juvenile form of neuronal ceroid lipofuscinosis (Spielmeyer-Vogt's disease) and in 15 healthy controls. In contradiction to recent reports normal activity of p-phenylene diamine mediated peroxidase was found in the patients. The possible role of contamination of the white cell preparation with hemoglobin is discussed.