Alicia Cervantes

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Cytogenetic studies have shown that 40-60% of patients with Ullrich-Turner syndrome (UTS) are 45,X, whereas the rest have structural aberrations of the X chromosome or mosaicism with a second cell line containing a structurally normal or abnormal X or Y chromosome. However, molecular analysis has demonstrated a higher proportion of mosaicism, and studies in(More)
OBJECTIVE To utilize United States birth certificate data (years 1989-1991) to examine the effects of race/ethnicity on twinning rates. STUDY DESIGN We used a database of birth certificate data for the United States (years 1989-1991) available on CD-ROM from the United States National Center for Health Statistics. This linked birth/infant death data set(More)
The cellular bases of the powerful cytolytic activity of the human protozoan parasite Entamoeba histolytica were explored by studying the effect of the virulent strain HM1:IMSS on epithelial monolayers of MDCK cells using a combination of time-lapse microcinematography and transmission and scanning electron microscopy. Early alterations of the epithelial(More)
46,XX maleness is characterized by the presence of testicular development in subjects who lack a Y chromosome. The majority of affected persons have normal external genitalia, but 10-15% show various degrees of hypospadias. Several hypotheses have been proposed to explain the etiology of this constitution: translocation of the testis-determining factor(More)
True hermaphroditism is characterized by the development of ovarian and testicular tissue in the same individual. Müllerian and Wolffian structures are usually present, and external genitalia are often ambiguous. The most frequent karyotype in these patients is 46,XX or various forms of mosaicism, whereas 46,XX is very rarely found. The phenotype in all(More)
Most individuals with the rare 46,XX male "syndrome" arise due to an unequal interchange between Xp and Yp termini during paternal meiosis. The pattern of Y-sequences in these patients varies considerably, but very few cases have been reported showing only SRY. The phenotype in these patients is also variable ranging from severe impairment of the external(More)
BACKGROUND AND AIMS Trisomy 21 is the most frequent genetic cause of intellectual disability. It is caused by different cytogenetic aberrations: free trisomy, Robertsonian translocations, mosaicism, duplication of the critical region and other structural rearrangements of chromosome 21. The aim of the study was to identify in Mexican trisomy 21 patients who(More)
Ring chromosomes are present in 1 in 25,000 human fetuses; 99% arise de novo while less than 1% of rings are inherited. This chromosomal rearrangement may arise through a cytogenetic mechanism involving breaks in chromosome arms and fusion of the proximal broken ends, leading to a loss of distal material. Most patient Y ring chromosomes are present in a(More)
In recent years, associat ions have been established between the HLA-sys tem and many diseases (1) some of the bet ter studied being the rheumato id diseases (2). Of these entities, the degenerative osteo-ar thr i t is associated with Heberden ' s nodes has been found to be associated with an increased prevalence of H L A B8 and with a decrease in H L A B17(More)
We describe a 4-year-old boy with partial 3q trisomy and distal 8p monosomy. The patient presented with mental retardation, dysmorphic face, congenital heart defect, brain and genital anomalies, and behavioral problems. The conventional cytogenetic analysis showed a 46,XY,add(8p) karyotype. Reverse painting and microsatellite analysis demonstrated a partial(More)