ABSTRACT
Nonmosaic trisomy involving 19p13.3p13.2 is a very uncommon abnormality. At present, only 12 cases with this genetic condition have been reported in the literature. However, the size of the trisomic fragment is heterogeneous and thus, the clinical spectrum is variable. Herein, we report the clinical and cytogenetic characterization of a 5-year-old boy with nonmosaic trisomy 19p13.3p13.2 (7.38 Mb), generated by a derivative Y chromosome resulting from a de novo unbalanced translocation t(Y;19)(q12;p13.2). We demonstrated the integrity of the euchromatic regions in the abnormal Y chromosome to confirm the pure trisomy 19p. Our patient shares some clinical features described in other reported patients with pure trisomy 19p, such as craniofacial anomalies, developmental delay, and heart defects. Different to previous reports, our case exhibits frontal pachygyria and polymicrogyria. These additional features contribute to further delineate the clinical spectrum of trisomy 19p13.3p13.2.
Subject(s)
Chromosomes, Human, Pair 19/genetics , Chromosomes, Human, Y/genetics , Lissencephaly/genetics , Polymicrogyria/genetics , Translocation, Genetic/genetics , Trisomy/genetics , Child, Preschool , Humans , Lissencephaly/pathology , Male , Mosaicism , Parents , Polymicrogyria/pathology , Trisomy/pathology , Young AdultABSTRACT
BACKGROUND: Genetic amniocentesis is performed in México 25 years ago but only few works have been published. OBJECTIVE: To analyze clinical and cytogenetic findings in consecutive patients submitted to genetic amniocentesis. MATERIAL AND METHOD: An analysis was made of the clinical features, amniocentesis results and pregnancy outcome in 1500 consecutive cases of genetic amniocentesis. RESULTS: Sixty-eight fetuses with chromosomopathy (4.5%) were detected and two, with an inborn error of metabolism. The most frequent abnormalities were trisomy 21 (32 cases), trisomy 18 (10 cases), trisomy 13(6 cases), 45,X (6 cases), 47,XXY (4 cases). Pregnancy outcome is known in 474 patients (32%). There were five fetal losses (1%). Of the 68 cases with chromosomopathy, the outcome is known in 45, of which, 29 (64%) decided to have an abortion while 16 (35%) continued the pregnancy, six had a spontaneous abortion or perinatal death and ten had an alive new born. Among fetuses with normal or balanced karyotype and normal ultrasound, 11 out of 419 (2.6%) had congenital anomalies. Two of them had a condition known to be related with epigenetic regulation, (Russell Silver and Angelman syndrome). CONCLUSIONS: Amniocentesis is a reliable and low risk method. Cytogenetic findings in this series are similar to those reported in the literature. Most patients with fetal disease decided to have an abortion. The finding of two patients with a condition related with abnormal epigenetic regulation suggests that the magnitude of this risk remains to be defined.
Subject(s)
Amniocentesis , Chromosome Disorders/diagnosis , Abortion, Eugenic , Adult , Amniocentesis/adverse effects , Amniocentesis/statistics & numerical data , Chromosome Disorders/embryology , Chromosome Disorders/genetics , Female , Fetal Death/epidemiology , Gestational Age , Humans , Infant, Newborn , Karyotyping , Mexico , Middle Aged , Mucopolysaccharidosis VII/diagnosis , Mucopolysaccharidosis VII/embryology , Mucopolysaccharidosis VII/genetics , Niemann-Pick Diseases/diagnosis , Niemann-Pick Diseases/embryology , Niemann-Pick Diseases/genetics , Obstetric Labor, Premature , Pregnancy , Pregnancy Outcome , Pregnancy, Multiple , Retrospective Studies , Risk , Ultrasonography, Prenatal , Young AdultABSTRACT
The t(12;21) produces the gene fusion ETV6/RUNX1 and is a frequent rearrangement in childhood ALL, associated with a good prognosis. In Mexico its prevalence has not been reported. This study evaluated a group of consecutive Mexican children with newly diagnosed ALL, to detect the fusion using fluorescence in situ hybridization (FISH). Seventy-one bone marrow samples were analyzed with FISH, using ETV6/RUNX1 DNA probes. Abnormalities of ETV6, RUNX1, or both were found in 31 of the 71 (44%) patients. Six showed ETV6/RUNX1 fusion and 17, with extra RUNX1 copies, presented an additional chromosome 21 or dup(21)(q22). Five patients had structural changes in ETV6, and three patients showed extra copies of ETV6 and RUNX1 from polysomy of chromosomes 12 and 21. Our results revealed a fusion in 8.5% of the 71 cases analyzed. This frequency is lower than that observed in other populations (9.5-32%). The structural rearrangements resulting in RUNX1 extra copies were found in 9.8% of patients, which is close to the range reported (1.5-9.7%) by other authors. Due to the prevalence of RUNX1 overrepresentation in our population and its unknown prognostic significance, further studies should be conducted in consecutive children with ALL, to correlate this abnormality with the patients' follow-up.
