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Biomedical subjects

H Rivera

Publications and source records attributed to H Rivera.

At least 163 records · Page 9Linked to original sources
PubMed1981

Trisomy 22q12 leads to qter: "aneusomie de recombinaison" of a pericentric inversion.

A 10-day-old girl affected with 22q12 leads to qter "pure" trisomy as a consequence of recombination within a maternal pericentric inversion (22)(p13q12) is described. A phenotypical comparative analysis reveals that the proposita's phenotype is strikingly similar to that of the trisomy 22 syndrome. Arylsulphatase-A activity was above normal levels and interpreted to be the result of a triple dosage of the gene, whose localization would be within the 22q12 leads to qter segment. It is concluded that the segment 22q12 leads to qter, rather than band q11 as previously suggested, plays an important role in determining the phenotypical abnormalities which characterize the trisomy 22 syndrome.

Abnormalities, Multiple↗
PubMed1981

Simultaneous trisomy 10q24 leads to qter and monosomy 4p16: an example of epistasis at the chromosome level.

A family with a reciprocal translocation (4;10)(p16;q24) leading to a simultaneous 10q24 leads to qter trisomy and partial 4p16 monosomy in two females (niece and aunt) is described. Comparative analysis with previously reported cases corroborates a distinctive dysmorphic syndrome due to the 10q24 leads to qter trisomy whose phenotypical expression is dominant over that of the 4p16 monosomy and those produced by other partial monosomies. This phenomenon is interpreted as epistasis at the chromosome level.

Abnormalities, Multiple↗
PubMed1980

Peutz-Jeghers syndrome with feminizing sertoli cell tumor.

A case involving a 6-year-old boy with Peutz-Jeghers syndrome and an unilateral feminizing Sertoli cell tumor is described. Endocrinologic studies revealed consistently high plasma and urine levels of estrogens and normal levels of testosterone and dihydrotestosterone. The increased levels of estrogens did not show changes that could be correlated with exogenous gonadotropin administration, thus indicating an autonomous nature. The histopathologic studies of nontumorous testicular tissue revealed changes in the seminiferous tubules which suggested that estrogens, directly or indirectly, may have had both stimulating and atrophying effects. It is concluded that gonadal tumors are in additional manifestation of the Peutz-Jeghers syndrome gene in both male and female patients.

Androgen-Insensitivity Syndrome↗
PubMed1980

Partial trisomy and monosomy 21 in an infant with an unusual de novo 21/21 translocation.

A 3-month-old boy with a 46,XY,--21,+t(21;21)(pter leads to q22.3::q22.3 leads to q11::p11 leads to pter) karyotype, implicating trisomy for the 21q11 leads to 21q22.2 segment and monosomy for the 21q22.3 sub-band, is described. Most of the clinical features corresponded to Down syndrome ; other signs such as large ears, prominent nasal bridge and retromicrognathia were interpreted as the expression of 21q22.3 monosomy. The abnormal monocentric chromosome had satellites and stalks on both ends as a result of a 21q;21q translocation followed by deletion of one centromere region. Despite similar stalk size and NOR-Ag positiveness a significantly higher association frequency of the centrometric end as compared to the acentric end was found. This observation suggests that the satellite association phenomenon is not exclusively NOR-dependent, but that the centromeric and/or p11 regions of acrocentrics also play an important role.

Centromere↗
PubMed1980

Guadalajara camptodactyly syndrome. A distinct probably autosomal recessive disorder.

Two sisters, aged 18 and 11 years, were found to have an intrauterine growth retardation-malformation syndrome which included camptodactyly as a typical sign. The overall analysis of the clinical and radiological findings permitted the individualization of a distinct entity. The family data suggested autosomal recessive inheritance.

Abnormalities, Multiple↗
PubMed1979

Some clinical and cytogenetic observations on a ring chromosome 13 (p11 q34).

A girl of 9-10/12 years of age with 46,XX,r(13)(p11q34) karyotypes was studied. She presented some clinical and radiological features, such as pectus excavatum, scalp alopecic area, 12th rib agenesis, hypoplastic pelvis, small gluteal pits and hypoplasia of the external genitalia in a female, which have never been previously described in other cases with ring 13 chromosomes. Cytogenetically, in vivo and in vitro viability of complete monosomic and partially trisomic and tetrasomic cells was found. The presence of nucleolus organizer regions and association of the ring 13 with other acrocentrics question the exclusivity of these attributes to acrocentrics p12.

Abnormalities, Multiple↗
PubMed1979

Malformed genitalia in the 47,XYY genotype.

A 5 10/12 year-old boy with a 47,XYY karyotype, micropenis, scrotal hypospadias and right testicular regression is described. Normal for age basal plasma testosterone levels which increased after hCG stimulation were interpreted as an adequate response of the left testicular Leydig cells. The review of similar cases did not permit definite conclusions concerning the relationship between the abnormal genitalia and the XYY karyotype.

Aneuploidy↗
PubMed1979

Hemolytic anemia caused by glucose-6-phosphate dehydrogenase deficiency.

Results are reported concerning quantitation of glucose -6- phosphate dehydrogenase (G6PD) enzyme activity where in one of the members of a family a clinical diagnosis of acute hemolytic anemia due to G6PD deficiency had been established. In the propositus, G6PD levels were found to be less than 10 per cent thus confirming diagnosis; the same enzymatic deficiency was identified in one of the siblings without a history of hematologic pathology and in a maternal cousin with a history of neonatal jaundice as well as two obliged carriers. Electrophoretical enzyme phenotype was similar to A variant in three affected males. Advantages of prevention and medical care possible with early diagnosis of G6PD deficiency are discussed.

Adolescent↗
PubMed1978

Galactosemia as a result of galactose-1-phosphate uridyltransferase deficiency.

This study was designed to determine the activity of galactose-1-phosphate uridyltransferase enzyme in a family (parents and eight children): four of these with clinical diagnosis of classical galactosemia. In two of them a complete transferase deficiency was found, thus confirming diagnosis; the other two, a pair of dizygotic twins, who since birth up to 11 years of age had been on a galactose free diet, showed enzymatic activity consistent with normal heterozygotes, one of them, and with normal homozygotes, the other. The parents and four brothers had the same enzyme activity levels an those found in heterozygotes for galactosemia. Early diagnosis is of utmost importance in classical galactosemia, and we emphasize this point because patients can be treated with dietotherapy and primary prevention is possible through genetic counseling.

Adolescent↗