RESUMO
We present an evaluation of the diagnosis, management and outcome of a pair of heterokaryotypic monozygotic dichorionic twins. The heterokaryotype was an incidental finding from an amniocentesis performed for prenatal diagnosis of beta-thalassaemia major in a pair of dichorionic twins. Monozygocity was revealed by QF-PCR showing identical short tandem repeat markers on chromosomes 21, 18, 13, X and Y. The twins were heterokaryotypic for duplication chromosome 2q13-q23.3, as shown by array comparative genomic hybridization. Selective foeticide was performed. This case demonstrates that heterokaryotypic monozygotic dichorionic twins are a genetic possibility that does occur.
Assuntos
Cromossomos Humanos Par 2 , Duplicação Gênica , Testes Genéticos , Achados Incidentais , Diagnóstico Pré-Natal/métodos , Gêmeos Monozigóticos/genética , Talassemia beta/diagnóstico , Adulto , Amniocentese , Hibridização Genômica Comparativa , Feminino , Aconselhamento Genético , Idade Gestacional , Humanos , Cariotipagem , Reação em Cadeia da Polimerase , Gravidez , Redução de Gravidez Multifetal , Talassemia beta/genéticaRESUMO
OBJECTIVE: To study the role of chromosomal aberration in the causation of recurrent spontaneous abortion (RSA) in Chinese population. METHODS: A total of 514 Chinese couples with 2 or more spontaneous abortions at less than 24 weeks of gestation were included. For each proband, a minimum of 13 metaphases were analyzed by G-banding. Additional cells (usually 50-100 cells) were screened when mosaicism was suspected. Chi 2 test was used to compare the number and frequency of couples with and without balanced translocation with respect to whether liveborn was present or absent. Chi 2 test for trend was used to show whether a correlation existed between the occurrence of balanced translocation and the number of spontaneous abortions at ascertainment. RESULTS: The overall incidence of chromosome anomaly was 51 out of 514 (9.92%). Chi 2 test for trend analysis showed that the chance of one member of a couple being a balanced carrier increased with the number of spontaneous abortions. The chance of finding translocation in couples with liveborn was higher than that in couples without liveborn, but the difference was not statistically significant. We also found that pericentric inversion 9 did not play an important role in the causation of recurrent abortion. CONCLUSIONS: Cytogenetic analysis is indicated in couples with 2 or more spontaneous abortions and the chance of finding chromosomal aberration increases with the number of abortions at the time of ascertainment.
Assuntos
Aborto Habitual/genética , Mosaicismo , Translocação Genética , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 19 , Feminino , Humanos , Masculino , GravidezRESUMO
We report on a newborn baby with partial trisomy 13 who presented with multiple dysmorphic features and hyperinsulinaemic hypoglycaemia. Cytogenetic study on peripheral blood lymphocytes showed 47,XY,+mar in all cells analysed; fluorescent in situ hybridisation showed that the marker was solely derived from chromosome 13. The final karyotype was 47,XY,+del(13)(q14q32). Milk formula through a nasogastric drip and intravenous glucose infusion were given to prevent further hypoglycaemia. However, the baby developed occasional episodes of hypoglycaemia during bolus feeding. Hence, diazoxide was given, at a dosage of 10 mg/kg per day from day 24. Thereafter, no hypoglycaemic episodes were detected. Subsequent follow-up revealed satisfactory growth, global developmental delay, and left divergent squint.
Assuntos
Cromossomos Humanos Par 13 , Hiperinsulinismo/genética , Hipoglicemia/genética , Trissomia/diagnóstico , Anormalidades Múltiplas/genética , Anormalidades Craniofaciais/genética , Humanos , Recém-Nascido , MasculinoRESUMO
The records of 40 nongrowing open bite patients treated with orthodontics and maxillary surgery were divided into two groups and evaluated. The extrusion group (n = 19) included those patients who had presurgical maxillary incisor extrusion of at least 1.5 mm. In the nonextrusion group (n = 21), the maxillary incisors were maintained or intruded prior to surgery. Statistical analysis showed no relationship between presurgical extrusion of the maxillary incisors and the stability of open bite correction; the maxillary incisors were generally stable long term in both groups. Overbite decreased a mean of -0.97 mm in the extrusion group and -0.67 mm in the nonextrusion group during the mean 5-year 10-month follow-up period after appliance removal. Twenty-five percent (10 of 40, 5 from each group) of the sample had no incisal overlap long term. These findings suggest that a moderate amount of presurgical incisor extrusion or lack of extrusion are stable long term and have little influence on posttreatment stability of open bites. The decrease in overbite observed after treatment may result from the influence of various dental, skeletal, and soft tissue factors rather than from any single factor.