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Biomedical subjects

S Kofman-Alfaro

Publications and source records attributed to S Kofman-Alfaro.

At least 55 records · Page 3Linked to original sources

[Familial Yqs chromosome in 4 generations].

A structural aberration of the Y chromosome (Yqs) was identified in a 4-year-old child who visited a physician for right unilateral cryptorchidism. The structure of this chromosome was determined through bands C, G and NOR. The family cytogenetic study allowed for the detection of the Yqs in up to four generations. A comparison is made of the different phenotypes associated with this marker in the medical literature, concluding that this is probably due to another polymorphism of the Y chromosome.

Child, Preschool↗

Endocrine and immunogenetic evaluation of an XX male infant with perineoscrotal hypospadias.

To clarify the origin of the genital ambiguity occasionally associated with the XX male syndrome, a series of endocrinological studies were undertaken in an affected 6 months old infant with perineoscrotal hypospadias. The patient fulfilled all the diagnostic criteria of the syndrome: the testes were descended bilaterally, the Mullerian derivatives were absent, the 46,XX chromosome complement was ascertained in different cell lines, and male levels of H-Y antigen were detected in cultured skin fibroblasts. Circulating gonadotrophin levels and pituitary LRH responsiveness were within normal limits for the age group. Serum testosterone (T) levels were normal, and gonadal stimulation with hCG caused a significant rise on serum T. Incubations of [3H]T with fibroblasts from genital skin revealed normal activity of steroid 5 alpha-reductase. Moreover, normal concentrations of thermostable cytosol androgen receptors were revealed in cultured fibroblasts. Altogether the results indicated that ambiguity of the external genitalia in this patient was the result of neither abnormal T biosynthesis, peripheral A-ring T reduction, nor androgen intracellular specific binding, and suggested that the nature of the incomplete virilization could be a non-endocrine independent event associated to this disorder. The data are also consistent with the notion that testicular impairment observed in adult XX males develops later in life.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

46,XX gonadal absence: a variant of the XX pure gonadal dysgenesis?

Two unrelated 46,XX individuals with female phenotype and sexual infantilism were studied. Endocrine findings showed anoestrogenism and hypergonadotrophism with a normal pituitary response to LRH. Laparotomy disclosed ovarian absence with normal Mullerian derivatives and no gonadal streaks were found within the true pelvis or inguinal canals. This condition represents the 46,XX counterpart of the 46,XY gonadal absence syndrome. Whether the XX agonadism reported here is a different and distinctive entity or is a variant of the XX pure gonadal dysgenesis syndrome can not be ascertained at present.

Adult↗

Inherited male pseudohermaphroditism due to gonadotrophin unresponsiveness.

An inherited form of incomplete male pseudohermaphroditism was studied in two post-pubertal and one pre-pubertal sibling. All patients presented a 46XY karyotype infantile female external genitalia, lack of breast development and sexual hair. Persistently elevated serum levels of gonadotrophins with normal pituitary responsiveness to LRH were found. Serum 17-OH progesterone, androstenedione, and testosterone levels were extremely low before and after gonadal stimulation with hCG. Laparotomy revealed absence of Wolffian and Mullerian derivatives. Testes were small and cryptorchidic. Microscopic and ultrastructural examination revealed seminiferous tubules with absence of spermatogenesis and normal Sertoli cells. The interstitial spaces were mainly occupied by poorly differentiated cells although in the post-pubertal patients there were small and randomly distributed nodules of Leydig cells without crystaloids. Incubation of testicular tissue from one post-pubertal patient with [14C]acetate showed lack of 14C-incorporation into appropriate steroid carriers. These data were interpreted as demonstrating that gonadotrophin resistance was the underlying abnormality of this syndrome, representing the human counter part of the "vet" pseudohermaphroditic rat.

Adolescent↗

Gynecomastia as a familial incomplete male pseudohermaphroditism type 1: a limited androgen resistance syndrome.

Four postpubertal 46 XY male patients with an inherited form of bilateral gynecomastia were studied to delineate the nature of the disease. Normal serum FSH and moderately elevated serum LH with concomitantly increased circulating levels of testosterone (T) and estradiol (E2) were found persistently in all cases in blood samples drawn at frequent intervals. LRH pituitary stimulation resulted in an exaggerated LH response and a normal FSH response. Chronic administration of T-cyclopentylate failed to decrease serum LH levels. The peripheral conversion rate of androstenedione to estrone was within normal limits. All patients had low ejaculate volumes with relatively normal spermatozoa counts. Testicular biopsies revealed normal Leydig cells and complete spermatogenesis. Urological examination disclosed that the prostate gland was extremely small. The breast tissue demonstrated the presence of tubular structures as well as the specific binding of [3H]T and [3H]dihydrotestosterone (DHT), which was inhibited by nonlabeled T, DHT, E2, and progesterone, but not by cortisol. The pedigree suggested a recessive X-linked inherited trait. A patient with a nonfamilial form of gynecomastia served as a control in all studies. These data were interpreted as demonstrating that this inherited type of gynecomastia represents the mildest expression of the androgen resistance syndromes and, therefore, belongs to the type 1 form of familial incomplete male pseudohermaphroditism.

Adolescent↗

46,XX sex reversal.

In humans, sexual differentiation is directed by SRY, a master regulatory gene located at the Y chromosome. This gene initiates the male pathway or represses the female pathway by regulating the transcription of downstream genes; however, the precise mechanisms by which SRY acts are largely unknown. Moreover, several genes have recently been implicated in the development of the bipotential gonad even before SRY is expressed. In some individuals, the normal process of sexual differentiation is altered and a sex reversal disorder is observed. These subjects present the chromosomes of one sex but the physical attributes of the other. Over the past years, considerable progress has been achieved in the molecular characterization of these disorders by using a combination of strategies including cell biology, animal models, and by studying patients with these pathologic entities.

Animal Diseases↗

Evidence that AEC syndrome and Bowen--Armstrong syndrome are variable expressions of the same disease.

Several clinical disorders combine ectodermal dysplasia (ED) and cleft lip and/or palate (CL/P). These conditions have been recognized as a group of diseases with a narrow phenotypic spectrum and multiple points of overlap. We report a patient with a clinical diagnosis of AEC syndrome (ankyloblepharon, ectodermal defects, and CL/P) who additionally has some features observed in a different ED-CL/P disorder, Bowen-Armstrong syndrome. Because of this clinical overlap, we suggest that AEC syndrome and Bowen-Armstrong syndrome may be variable manifestations of the same pathologic entity.

Bowen's Disease↗

Phenotypical expression in XX males correlates with testicular response to exogenous choriogonadotropin in early infancy: does a variable degree of testicular failure determine the degree of genital ambiguity?

The 46,XX male syndrome is characterized by the presence of testicular development in subjects who lack a Y chromosome. The majority of patients have male external genitalia without ambiguity; however, 10-15% show diverse degrees of hypospadias. Testicular function is normal at birth but deteriorates thereafter. However, it has not been clarified why some cases exhibit genital ambiguity. This study examined 10 affected patients, including 4 prepubertal (< 1 year old) with hypospadias (1 glandular, 1 penile, and 2 penoscrotal). In all subjects, testicular function was evaluated by performing a stimulation with choriogonadotropin. In the postpubertal individuals, basal and poststimuli testosterone were below the reference values. Prepubertal patients had age-appropriate basal test-osterone concentrations. All responded to the choriogonadotropin challenge; however, the most significant response was observed in the patient with the glandular hypospadias, the second highest response was presented by the patient with the penile hypospadias, while both patients with the penoscrotal hypospadias had the poorest responses. These results suggest that the degree of genital ambiguity is correlated with the impairment in testosterone response to choriogonadotropin in early infancy, indicating a defect in testosterone production in XX males with genital ambiguity.

Adolescent↗

[Clinical, cytogenetic, endocrinological and histological studies in true hermaphrodites].

The clinical, cytogenetic, endocrinological and histologic features of nine mexican patients with true hermaphroditism are reported. Ages at admission ranged from 10 months to 27 years; in seven cases a male sex of rearing was documented, being 46,XX (n = 6) the most frequent karyotype. Basal levels of gonadotrophins, gonadal steroids, and the testosterone response to exogenous HCG varied depending upon age as well as with type and functional status of the gonadal tissue. However, ovarian tissue always preserved its function better than the testicular tissue did. In one of the patients who presented cyclic hematuria, spontaneous ovulation was documented by serum progesterone monitoring (progesterone = 4.3-11.0 ng/mL during luteal phase). Ovo-testis was the most common gonad present; in four cases bilateral ovo-testes were found. Internal genitalia varied depending on the existing gonad, although in all cases a uterus was found. These findings are in accordance with previous reports of individuals bearing true hermaphroditism in other populations.

Adolescent↗