RESUMEN
OBJECTIVE: To describe a novel unbalanced X;21 translocation resulting in a derivative pseudodicentric chromosome X;21 lacking the critical region for ovarian development and function, in a 16-year-old girl referred for cytogenetic analysis due to primary amenorrhea and Turner-like features. METHODS: Cytogenetic analysis of the proband and her parents was performed on peripheral blood lymphocytes by GTG banding. Molecular cytogenetic FISH analysis was performed on metaphase preparations, using X chromosome centromeric probe and telomeric and pancentromeric peptide nucleic acid (PNA) analog probes. The HUMARA assay as well as methylation studies for PCSK1N and FMR-1 loci were performed. RESULTS: Cytogenetic analysis revealed a de novo unbalanced X;21 translocation, described as 45,X,der(X)t(X;21)(q22.2;p11.2),-21. FISH analysis showed that the derivative X chromosome carried both the X and 21 centromeres, as well as, the Xp and 21q telomeres. The karyotype was thus reevaluated as 45,X,psu dic(21;X)(21qterâ21p13::Xq22.2âXpter),-21. X inactivation studies revealed that the derivative chromosome was of paternal origin and confirmed the selective inactivation of the derivative X segment of the pseudodicentric chromosome. CONCLUSIONS: Primary amenorrhea and other Turner-like characteristics of the proband are apparently due to the loss of the Xq22.2âXqter critical region which contains critical genes for the ovarian development and function. The chromosome X segment of the derivative pseudodicentric chromosome is selectively inactivated, but inactivation does not seem to spread onto the translocated chromosome 21, accounting probably for the lack of severe clinical consequences which would result from monosomy 21.
Asunto(s)
Cromosomas Humanos Par 21/genética , Cromosomas Humanos X/genética , Translocación Genética/genética , Síndrome de Turner/genética , Adolescente , Femenino , Humanos , Hibridación Fluorescente in Situ , Síndrome de Turner/fisiopatologíaRESUMEN
OBJECTIVES: To study potential differences in the clinical and microbiological features of hospitalized elderly patients with acute pyelonephritis with and without diabetes mellitus. DESIGN: Retrospective review of medical records. SETTING: University hospital. PARTICIPANTS: Eighty-eight patients aged 65 and older with diabetes mellitus (DM) (57 female; 64.8%) and 118 controls without DM (75 female; 63.6%), matched for age and sex, hospitalized with acute pyelonephritis between January 1997 and December 2005. MEASUREMENTS: Medical records were reviewed for demographic, clinical, and microbiological characteristics. RESULTS: The median age of both groups was 74 (range 65-95). Twenty-seven people with DM (30.7%) and 13 controls (11.0%) had bacteremia (P=.001). People with DM had longer fever (median 4.5 vs 2.5 days; P<.001), longer hospitalization (median 10 vs 7 days; P<.001), and greater mortality (12.5% vs 2.5%; P<.01) than controls. Logistic regression analysis proved DM to be an independent predictor of bacteremia, long hospitalization, and mortality. Escherichia coli was the most common microorganism found in both groups, whereas Candida spp. were implicated more frequently in people with DM than controls (12.7% vs 1.7%; P<.01). Antimicrobial resistance did not increase over the study period. CONCLUSION: Acute pyelonephritis in elderly people with DM is associated with risk of bacteremia, long hospitalization, and mortality.