Partial distal 5p trisomy resulting from paternal translocation (5;15)(p15.1;p13) in a boy with no mental retardation

We report a boy with partial distal 5p15.1-->pter trisomy and normal development. We compared the clinical findings in our patient with those previously reported of the same 5p duplicated region. Several cases of autosomal duplications and normal development have been described. The present case is another example of a chromosomal anomaly with little, if any, phenotypic effect without mental retardation.     

A fetus with trisomy 9p and trisomy 10p originating from unbalanced segregation of a maternal complex chromosome rearrangement t(4;10;9)

Complex chromosome rearrangements are only rarely seen in constitutional karyotypes. A case of prenatally detected trisomy 9p with trisomy 10p originating from adjacent segregation of a maternal complex chromosome rearrangement is reported. Ultrasound examination at 18 weeks of gestation showed cleft lip palate, club feet, structural anomalies of the cerebellum and cystic kidneys. Cytogenetic analysis of amnion cells revealed a female fetus with 47,XX,+der(9). FISH analyses together with parental karyotyping demonstrated the fetal additional chromosome to originate from malsegregation of a maternal complex chromosomal rearrangement. The mother is carrier of a balanced translocation t(4;10;9) (q12; p11;q13). Postmortem examination of the fetus showed nose anomalies, cleft lip palate, low set ears, club feet, lung anomalies, cystic kidney and aplasia of the uterus. Reporting of such rare cases is important in order to enable this information to be used for genetic counselling in similar situations.     

Prenatal diagnosis and fetal pathology of partial trisomy 20P-monosomy 4P resulting from paternal translocation

Amniocentesis was performed in view of a paternal balanced chromosomal rearrangement t(4;20)(p16;p12), inv(18)(p11q11). The pregnancy was complicated by severe oligohydramnios. The fetal karyotype was unbalanced: 46XX, der(4), t(4;20)(p16;p12), inv(18) (p11q11)pat., thus resulting in partial trisomy 20p and monosomy 4p. In addition, the amniotic fluid alpha-fetoprotein (AFP) became increasingly elevated with gestational age. The pregnancy was terminated at 25 weeks. The fetus presented with typical facial dysmorphic features, unilateral cleft lip and palate, severe renal hypoplasia, consistent with the 4p-(Wolf-Hirschhorn) syndrome.     

A patient with a de novo t (6;9) and an interstitial duplication of (9)(q21.2q22.1).

We report on a 4-year-old child with psychomotor retardation, general hypotonia and only mild dysmorphic features. Her chromosome constitution was 46,XX, t (6;9) (q27;q22.1), dup (9) (q21.2q22.1). This de novo interstitial duplication was confirmed using fluorescence in situ hybridisation (FISH) with band-specific probes. This is the second report of a patient with an interstitial duplication of this region of the long arm of chromosome 9. It is concluded that in a child with an abnormal phenotype and a de novo (apparently) balanced translocation, the possibility of a small duplication or deletion should be considered.     

Pre- and perinatal findings in partial trisomy 7q resulting from balanced parental translocations t(7;21) and t(4;7)

We report on a fetus and a newborn, both with partial trisomy 7q21-->qter due to different familial translocations, t(7;21)(q21.2;p12) and t(4;7)(q35;q21.2). Postmortem examination of the 19-week-old female fetus disclosed dysmorphic features, cleft palate, anomalies of the great vessels, intestinal malrotation and uterus bicornis. The newborn girl revealed a pattern of minor anomalies, cleft palate, cerebellar hypoplasia, and anomalies of pancreas, gall bladder and appendix. The clinical findings in three other reported fetuses with partial trisomy 7q described so far are reviewed. A duplication 7q21-->qter, as found in the propositi, has only been described in 11 patients who all had a concurrent partial monosomy. Patient 1 is particularly interesting since she is, to our knowledge, the first reported case with pure trisomy 7q21/22-->qter. We reviewed the phenotype of the previously described patients, compared it with the propositae, and summarized the clinical features of pure trisomy 7q21/22-->qter.     

Bilateral renal agenesis and fetal ascites in association with partial trisomy 13 and partial trisomy 16 due to a 3:1 segregation of maternal reciprocal translocation t(13;16)(q12.3; p13.2).

A female fetus with bilateral renal agenesis and fetal ascites was found to have partial trisomy 13 (pter-q12.3) and partial trisomy 16 (p13.2-pter), 47,XX,+der(13)t(13;16)(q12.3; p13.2)mat. The chromosomal aberration was due to a 3:1 segregation with tertiary trisomy transmitted from a maternal reciprocal translocation 13;16. Prenatal ultrasound of a 29-year-old, gravida 2, para 0 woman at 22 gestational weeks showed fetal ascites, severe oligohydramnios and non-visualization of fetal urinary bladder and kidneys. The pregnancy was terminated. At delivery, the proband displayed dysmorphic features of hypertelorism, a prominent glabella, epicanthic fold, a stubby nose with a depressed nasal bridge, anteverted nares, thin lips, micrognathia, low-set ears, a short neck and a distended abdomen. Necropsy confirmed bilateral renal agenesis and ascites. A cytogenetic study performed on fibroblasts obtained from the proband's skin revealed an extra supernumerary chromosome. The mother was later found to have a reciprocal translocation. Fluorescence in situ hybridization for a submicroscopic deletion in chromosome 22q11 in the proband was negative. The parents had no urological anomalies. Our observation further extends the clinical spectrum associated with proximal trisomy 13q and distal trisomy 16p. We suggest prenatal cytogenetic analysis in fetuses with urological anomalies, including renal agenesis, to uncover underlying genetic disorders.     

Analysis of chromosome abnormalities in sperm and embryos from two 45,XY,t(13;14)(q10;q10) carriers

Robertsonian translocation t(13q14q) is studied in sperm and embryos of two couples undergoing preimplantation genetic diagnosis (PGD) in which both males are carriers of the translocation. It is already known that the chances of achieving pregnancy for a translocation carrier are directly linked to the number of normal or balanced embryos available for replacement. In our work it was found that the frequency of balanced spermatozoa was almost identical in both patients (74 and 77%), and after PGD, the frequencies of abnormal embryos caused by the translocation were also similar. Sperm chromosome analysis in translocation carriers can provide a reasonable basis for estimating a baseline of chromosome abnormalities to be found in embryos during an assisted reproductive cycle. However, individual factors not linked to the translocation can also produce other chromosome abnormalities (mosaicism, haploidy, polyploidy) and may compromise the chances of achieving a viable pregnancy.     

Prenatal diagnosis of and midtrimester pathology with karyotype 46,XY,del(4)(q22q26). A case report

A prenatal diagnosis of an interstitial deletion with chromosome 4,46,XY,del(4)(q22q26) was obtained on amniotic fluid cells drawn at 19 weeks' gestation from a 35-year-old gravida. Counseling on the basis of unusual or tenuous data is always difficult, but comparisons with similar deletions in 4q suggested a substantial risk of anomalies. A comparison of the postabortal autopsy findings with those from other reported cases of interstitial deletions of chromosome 4q suggested different pathology with this area of deletion than previously reported for other areas of 4q.     

Mosaic trisomy (8)(p22 --> pter) in a fetus caused by a supernumerary marker chromosome without alphoid sequences

OBJECTIVE: Our objective was to characterise a marker chromosome in cultured amniocytes of a fetus with a mos 47,XX,+mar[3]/46,XX[14] karyotype. METHODS: The indication for prenatal cytogenetic analysis of cultured amniocytes was advanced maternal age. Classic banding techniques (GTG- and C-banding) were performed. Microdissection combined with reverse painting was used to disclose the exact origin of the marker; the result was confirmed by chromosome painting and FISH with band-specific probes. RESULTS: Analysis of GTG-banded chromosomes showed a small marker chromosome in 3 of the 17 colonies analysed. Subsequently, C-banding showed no alphoid sequences, suggesting the presence of a neocentromere. The parent's karyotypes were normal. After normal ultrasound findings, the parents decided to continue the pregnancy. Chromosome analysis in peripheral blood after birth demonstrated that the marker chromosome was present in 50% of the lymphocytes. Using microFISH, the marker was further characterised and appeared to be derived from chromosome region (8)(p22 --> pter). CONCLUSION: Accurate identification of the marker chromosome was very important for prenatal counselling. Combining the results of GTG- and C-banding analysis with the results of the (micro)FISH, we concluded that the patient's karyotype is: mos 47,XX,+mar.rev ish der(8)(p22 --> pter)[50]/46,XX[50].     

Male factor infertility associated with a familial translocation t(1;13)(q24;q10)

We report a case of a family with one sister and one brother in which the brother inherited a t(1;13)(q24;q10) translocation from his mother. We describe a case with a clear translocation between the long arm of chromosome 1 and the long arm of chromosome 13. It is possible that the APOE and MTHFR genotypes and lower folate status may also be responsible for the above mentioned translocation.     

Unbalanced cryptic translocation der(14)t(9;14)(q34.3;q32.33) identified by subtelomeric FISH

We investigated a girl with dysmorphic features and moderate developmental delay by subtelomeric FISH (fluorescence in-situ hybridization). We found an unbalanced cryptic translocation, t(9;14)(q34.3;q32.33), resulting in a subtelomeric deletion of 14q and duplication of 9q deriving from a balanced translocation in the mother. A review of the literature suggests that the phenotype of our case is related to the 14 qter deletion, without signs of concomitant partial trisomy 9. The case reinforces the value of subtelomeric screening for genetic counselling.