Identification of a supernumerary marker derived from chromosome 17 using FISH.

We report on a 15-year-old girl with mental retardation, obesity, short stature and minor anomalies. She had 47 chromosomes with a minute extra ring which was identified by FISH to be derived from chromosome 17.

Chromosome abnormalities in selected newborn infants with malformations in Brazil.

Between 1982 and 1985, 109 infants were referred for cytogenetic examination out of a population of 73,192 liveborn infants from eight maternity hospitals surveyed by the ECLAMC/MONITOR program. Thirty-one of the children had a chromosome abnormality different from trisomy 21. Considering the total population surveyed, trisomy 18 was detected in 1:6,099; trisomy 13 was seen in 1:24,397 and unbalanced rearrangements were found in 1:7,319 infants. Those rates were not significantly different from the expected ones, as compared to previous cytogenetic surveys of consecutive births. We concluded that most chromosome abnormalities associated with congenital malformations can be detected at low cost, provided there is a high accuracy of clinical examination and referral criteria, as well as close cooperation between pediatricians and geneticists.

[Ph1-positive acute myeloid leukemia de novo or blast crisis of chronic myeloid leukemia? Molecular analysis and clinical course of a case]. / Leucemia mielóide aguda Ph1-positivo de novo ou crise blástica de leucemia mielóide crônica? Análise molecular e evolução clínica de um caso.

A case of AML presented with basophilia in peripheral blood and Ph1 chromosome in karyotype analysis is reported. After one year of treatment with intensive chemotherapy and clinical and hematological remission, molecular analysis (RT-PCR) detected minimal residual disease (b2-a2 rearrangement). Thus, the patient relapsed as AML and, after second remission, he developed a hematological picture of chronic CML. Ten months later, he relapsed again as AML. The difficulties of diagnosis between AML Ph1-positive de novo and myeloid blast crisis of CML, as the first manifestation of disease, based on clinical and molecular aspects are discussed.

The human Y chromosome: its routine identification and variability.

Different criteria for identifying the human Y chromosome using only conventional staining techniques were evaluated and a procedure based on three of them was developed. It leads to correct identification in 93% of cells even without resorting to differences in size between the Y and the other G chromosomes. The variability in size of the human Y chromosome was assessed in a random group of White men. It was found to be significantly greater than that of all other chromosomes in the karyotype when the comparisons were made in such a way as to avoid the size-dependent component of variation.

Leucemia mielóide aguda Ph1-positivo de novo ou crise blástica de leucemia mielóide crônica? Análise molecular e evoluçäo clínica de um caso / Ph1-positive acute myeloid leukemia de novo or chronic myeloid leukemia? Molecular analysis and clinical evolution of a case

Os autores relatam um caso de leucemia mielóide aguda (LMA) que apresentava, ao diagnóstico, basofilia no sangue periférico e cariótipo com presença do cromossomo Filadélfia (Ph1). Após um ano de tratamento com quimioterapia intensiva e em fase de remissao clínica e hematológica, a análise molecular pela técnica da reaçao em cadeia da polimerase-trasncriptase reversa (RT-PCR) revelou presença de doença residual (rearranjo b2-a2). A seguir, o paciente apresentou primeira recidiva como LMA e, após a remissao, evoluiu com quadro hematológico sugestivo de leucemia mielóide crônica (LMC) em fase crônica. Após dez meses, apresentou nova recidiva da LMA. Os autores discutem a dificuldade do diagnóstico diferencial entre LMA Ph1-positivo de novo e crise blástica mielóide como primeira manifestaçao clínica da LMC, baseados nos aspectos clínicos e moleculares.