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S Kofman-Alfaro

Publications and source records attributed to S Kofman-Alfaro.

63 records · Page 4Linked to original sources
PubMedDate not supplied

[Molecular detection of chromosome Y DNA sequences in patients with Turner's syndrome].

The presence of Y-chromosome material in the genome of phenotypic females has been associated with an increased risk of developing gonadal tumors. To assess whether DNA sequences of the Y-chromosome are present in the genome of individuals with gonadal dysgenesis and clinical features of Turner's syndrome, we have studied three patients with 45, X/46, X, + mar chromosome complement, and two Turner patients with 45, X/46, XY and 45, X karyotypes who served as positive and negative controls, respectively. Molecular detection of Y-DNA sequences was done by DNA-DNA hybridization using the specific probes pY97 and pDP1007 as well as by polimerase chain reaction. The results revealed that the marker chromosome of one of the patients contained DNA sequences from the centromeric region of the Y-chromosome in a manner similar to that found in the 45, X/46, XY patient and in the male control; the gene ZFY was negative in this patient, and was probably lost when the ring chromosome was formed. In contrast, the ring chromosomes of the other two patients did not exhibit the presence of Y-chromosome material. The results were interpreted as demonstrating the Y-chromosome origin of the ring marker in one patient with gonadal dysgenesis, and suggest an X-chromosome origin of the ring markers in the other two patients. These data further underline the relevance of practicing molecular studies in these disorders which may help to determine appropriate therapeutic strategies.

Adult↗
PubMedDate not supplied

[Cytogenetic study of 22 adults and 3 children with acute lymphoblastic leukemia].

Between 1987 and 1990 cytogenetic studies of bone marrow and lymphocytes from peripheral blood from 25 patients with de novo ALL were performed. All cases had chromosomal aberrations; however in 23 patients a normal cell line was also present. The most important structural aberrations found were: t(17;19)(q11;p13), t(2;9;22)(q34;q34;11), t(1;7)(p13;q33), t(6;11)(q26;p16), t(3;4)(q24-25;q26), t(1;12)(q23;q34), t(2;18)(q15;p12), t(2;4)(q23;q35) and t(4;11)(q21;q23). These chromosome abnormalities correlate with the response to treatment and survival and improve the identification of high-risk patients. Our study shows the presence of some chromosomal abnormalities different to those reported in the literature; however the breakpoints involved seem to be the same which suggests that these critical regions may be directly involved in the pathogenesis of these disorders.

Adolescent↗
PubMedDate not supplied

[Progress in the knowledge on the genetic process of sexual differentiation in humans].

In humans, the first stage of sex differentiation is determined by the sex chromosomal constitution and the genes required in the pathway leading gonadal organogenesis. The interaction of SRY, ZFY and several autosomic and X-linked genes in this process is analyzed. It has been suggested that sex-differences are present immediately after fertilization. Sex differentiation depends on a cascade of complex molecular and morphological events that occur at the appropriate time and in the correct sequence during ontogeny.

Animals↗
PubMedDate not supplied

[Interferon in the eradication of the Philadelphia chromosome in chronic myeloid leukemia].

OBJECTIVE: To evaluate if human recombinant interferon alpha (IFN) combined with chemotherapy is able to suppress the Philadelphia chromosome clone in patients with chronic myeloid leukemia (CML). MATERIAL AND METHODS: The cytogenetic evolution in 53 patients with CML in chronic phase de novo was studied. They received one of three treatment schemes: a) induction of remission with daunorubicin, vincristine, cytosine arabinose and prednisone (DOAP) and maintenance with IFN (n = 12); b) induction with busulfan (BUS) or hydroxyurea (HYDX) and maintenance with IFN (n = 26); c) induction with DOAP and maintenance with BUS (n = 15). RESULTS: The remission was seen two to six months after the start of treatment: 10 had complete remission, six a partial one, 14 a minor remission and 23 none. The 16 with complete or partial response received treatment with IFN. None of the 15 cases maintained with BUS had complete or partial response. The proportion of cases with complete response (3/12) was slightly lower in patients treated with intensive chemotherapy (BUS/HIDX/IFN) than in those receiving conventional treatment (7/26). CONCLUSIONS: Our results showed that: a) IFN in combination with chemotherapy induced partial or complete response in 30% of our cases; and b) intensive chemotherapy combined with IFN was not superior in terms of a cytogenetic response to treatment with monodrugs (BUS/HIDX) and IFN.

Adolescent↗
PubMedDate not supplied

[Genetic heterogeneity and phenotypic variability in 46,XY sex reversal].

The discordance between the chromosomic and the gonadal-phenotypic sex is known as sex reversal (XX males and XY females). We review the XY pure gonadal dysgenesis characterized by female phenotype, primary amenorrhea and absence of secondary sexual development. Bilateral streak gonads are always present in the complete form of this syndrome, while variable degrees of virilization are found in the partial forms, depending on the severity of the testicular damage. A plausible explanation for this pathology are SRY mutations that interfere with the testicular differentiation. However, only 10-15% of the patients with the complete form show SRY mutations, particularly in the HMG box. The remaining cases are probably due to mutations in different autosomal or X-linked genes which are also involved in the sex differentiation cascade. Recently, it has been shown that mutations in several genes responsible of well known genetic entities as WT1, SOX9, DSS and SF1, result in sex reversal. These findings reveal the genetic heterogeneity and clinical variability of XY sex reversal and provide the basis establishing a hierarchy of genes and their participation in the sex determination pathway.

Female↗