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Biomedical subjects

F Rivas

Publications and source records attributed to F Rivas.

At least 55 records · Page 3Linked to original sources
PubMed1990

Hematological and biochemical studies in children with Down syndrome.

Eighty-three children with Down syndrome were submitted to hematological and biochemical studies; 69 normal children were included as controls. The variables analyzed were: HbF, HbA2, serum B12 vitamin (B12), folates, total iron and iron binding capacity, hematic cytology, and the red blood cell enzymes adenosine deaminase (ADA), glucose-6-phosphate dehydrogenase (G6PD) and superoxide dismutase (SOD). The most relevant results were: macrocytosis, normal leucocytes, HbF, B12 and folates, as well as high levels of the enzymes ADA and G6PD. An indirect association between macrocytosis, ADA and G6PD is discussed.

Blood Cell Count↗
PubMed1990

Increased adenosine deaminase activity in a patient with cartilage-hair hypoplasia.

A boy aged 9 years presenting short stature and recurrent respiratory-tract infections was studied. The clinical and roentgenological pictures allowed the diagnosis of cartilage-hair hypoplasia (metaphyseal chondrodysplasia, McKusick type). Biochemical studies disclosed a four-fold increase in adenosine deaminase activity, but without evidence of anemia. Immunological evaluation showed abnormal cellular but normal humoral immunity.

Abnormalities, Multiple↗
PubMed1990

[Effect of gene dosage on the glyceraldehyde-3-phosphate dehydrogenase enzyme (GAPD) in partial 12p13.3 pter trisomy].

A family with three brothers presenting 12p trisomy due to an adjacent-1 segregation of a paternal translocation (1;12) (q44;p12.2) is described. The patient's phenotype was compatible with the chromosomal imbalance including the gene dosage effect of the glyceraldehyde-3-phosphate dehydrogenase. The importance of the genetic counseling in these families is stressed.

Abnormalities, Multiple↗
PubMed1987

Inv(4)(p16q21). A five-generation pedigree with 24 carriers and no recombinants.

A familial inv(4)(p16q21) ascertained through a woman who had a thanatophoric dwarf daughter and two abortions is presented. She and 23 other relatives were carriers, but no recombinants were found. The proportion of abortions and neonatal deaths in carriers' offspring was similar to that in non-carriers. A random segregation of the inverted chromosome was observed. The analysis of the present and previous familial chromosome 4 pericentric inversions indicates that: the breakpoint in q, with a limit between q21 and q25 determines the occurrence of inherited unbalances, and most recombinant chromosomes have duplication of the larger distal segment.

Adult↗
PubMed1987

A distinct congenital motor and sensory neuropathy (neuronal type) with dysmorphic features in a father and two sons. A variant of Charcot-Marie-Tooth disease.

A 37-year-old male had clinical and electrophysiological features of hereditary motor and sensory neuropathy (neuronal type) with onset in infancy, as well as histological picture of neurogenic myopathy. Two sons, aged 2 and 3 4/12 years, showed congenital contraction deformities of feet, delayed motor development, and electrophysiological features similar to those of the father. All three also presented laryngeal abnormalities, peculiar facies, short neck, narrow shoulders and protruding chest. The authors conclude that this aggregate of anomalies constitutes a "new" syndrome probably due to an autosomal dominant gene.

Abnormalities, Multiple↗
PubMed1987

Ovarian dysgenesis due to an idic(X)(q2803).

A 17-year-old female patient with gonadal dysgenesis but no other turnerian features was found to have a 46,X,idic(X)(pter----q2803:q2803----pter) karyotype in her lymphocytes. Replication of the rearranged X was consistently late and symmetrical. It is postulated that the ovarian dysgenesis usually seen in nonmosaic carriers of Xq;Xq terminal rearrangements may be secondary to a nonreactivation of the abnormal chromosome before meiosis.

Adolescent↗
PubMed1987

Cytogenetic evaluation of 163 azoospermics.

A constitutional chromosomal aberration was diagnosed in 38/163 (23.3%) azoospermic patients. Whereas the 47,XXY complement was the commonest (31/38 cases), the following abnormal karyotypes were also found: 46,XX; 46,X,del(Y) (q11); 46,X,r(Y); 46,XY,inv(1) (p3500q21.3)mat; and 46,Y,t(X;3) (q26;q13.2)mat (both the deleted and the annular Y were observed twice). Pooled data from the literature showed that the frequency of chromosomal abnormalities is higher in azoospermic (150.4/1000) than in infertile (55.3/1000) males, which in turn is higher than in newborns (less than 6/1000). The observed different frequency between azoospermic and infertile individuals is given by several types of chromosomal abnormalities, mainly by the complement 47,XXY. The analysis also showed that the male infertility secondary to rob translocations and supernumerary marker chromosomes is usually not related to azoospermia. The contrary occurs in certain rcp and gonosome;autosome translocations and in autosome inversions.

Adult↗
PubMed1987

Familial trisomy 3q25----qter. Report of two cases.

Two girls with the trisomy 3q2 clinical syndrome are presented. Their fathers were twins and carried a t(3;8)(q25;p23). Case 1, aged 8 months, had a 46,XX,der(8) complement. Case 2, died at 5 months of age before cytogenetic study, was considered to have the same karyotype. Both cases combined showed the majority of phenotypical features of trisomy 3q2 syndrome, including facial appearance, glaucoma, and visceral malformations. This observation suggests that the trisomy 3q25----qter is sufficient to produce the syndrome which shows variable expression in these cases.

Chromosome Aberrations↗
PubMed1986

De novo del(6)(q25) associated with macular degeneration.

An eight-month-old girl with a de novo del(6)(q25) is described. She and other previous cases of 6q deletion showed concordance for developmental retardation associated with multiple unspecific congenital abnormalities, which do not yet allow the delineation of a syndrome. However, bilateral macular degeneration was found in the proposita and had been observed in another similar case, so it probably represents a distinctive feature of 6q terminal monosomy. This observation also suggests the existence of a dominant macular degeneration locus within 6q25----qter.

Abnormalities, Multiple↗
PubMed1986

Reciprocal translocations between acrocentrics: segregational analysis in twenty-nine families with unbalanced progeny.

This study comprises 29 families with 42 unbalanced offspring in which reciprocal interacrocentric translocations (RIATs) were identified by banding. The observed unbalances were due to adjacent-1 (42.9%), adjacent-2 (28.6%) and 3:1 (28.6%) segregations. The concordance between the observed and expected segregations was 85.7% according to the Jalbert et al. (1980) criteria. 17.2% of the RIATs led to unbalances by 2 different segregations. 78.6% of the cases were maternal in origin. The overall incidence of spontaneous abortion was 37%. Corrected recurrence risks of unbalanced liveborn offspring for female and male carriers were seemingly similar: 17.8% and 12.5% respectively. These data indicate that RIATS exhibit (as distinctive features) an approximate 4:3:3 ratio for adjacent-1, adjacent-2 and 3:1 segregations, and a proneness to produce unbalances by different segregations.

Abortion, Spontaneous↗
PubMed1985

Monosomy 13q32.3----qter: report of two cases.

Two unrelated patients with monosomy 13q32.3----qter are reported. Comparison with six similar cases previously published indicates that the craniofacial dysmorphism of the 13qter monosomy syndrome is related to band 13q34, the thumb hypoplasia to band 13q32, and an apparently different phenotype to band 13q33. Coagulation deficiency appears to be non-specific in monosomy 13qter.

Child, Preschool↗