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Biomedical subjects

H Rivera

Publications and source records attributed to H Rivera.

At least 145 records · Page 8Linked to original sources
PubMed1985

Trisomy 7p due to a mosaic normal/dir dup(7)(p13----p22). Syndrome delineation, critical segment assignment, and a comment on duplications.

A 4 4/12 year-old girl with a peculiar phenotype due to a 46,XX/46,XX, dir dup(7)(p1300----p2200) karyotype is described. The comparison with about ten similar cases permitted a better delineation of the 7p trisomy syndrome and the assignment of the band 7p21 as the critical one. Mechanisms for the origin of homogeneous and mosaic duplications, including one model based on a meiotic half chromatid duplication, are discussed.

Abnormalities, Multiple↗
PubMed1985

Familial inv(2) (p2300q11.2).

A hitherto undescribed inv(2) (p2300q11.2) was found in 2 generations of a family ascertained through a holoprosencephalic liveborn boy with normal karyotype. This inversion, quite probably not related to the child malformations, does not seem neither impair reproductive fitness nor to yield viable recombination aneusomies.

Chromosome Banding↗
PubMed1984

The phenotype in partial 13q trisomies, apropos of a familial (13;15)(q22;q26) translocation.

A 12 month-old male patient with a karyotype 46,XY,-15,+der(15),t(13;15)(q22;q26)pat is presented. His stillborn sib showed malformations compatible with the 13q deletion syndrome, probably due to a 46,XY,der(13) karyotype. Phenotypic analysis of 41 cases from the literature with partial distal 13q (D13q) trisomies indicate that the segment 13q22----qter in trisomy with or without another concomitant aneusomy is sufficient to produce the majority of the trisomy 13 syndrome features, some of which (cleft palate, increased HbF and projections in PMN) are present in different non-overlapping partial 13q trisomies. About 82% of the D13q trisomies are inherited, more frequently from the mother.

Adult↗
PubMed1984

A new form of hypertrichosis inherited as an X-linked dominant trait.

A family with a distinct form of congenital generalized hypertrichosis was studied. Males were more severely affected than females, who exhibited asymmetric hair distribution. This finding was attributed to lyonization, since genealogical studies indicated an X-linked pattern of inheritance. A back mutation is postulated as the origin of this new phenotype.

Adolescent↗
PubMed1984

Familial inv(1) (p3500q21.3) associated with azoospermia.

An inv(1) (p3500q21.3) was found in an azoospermic man, his mother and two other maternal relatives. Although the mechanisms involved are still unclear, it is stressed that pericentric inversions of chromosome 1 in which the inverted chromosome becomes submetacentric (centromeric index less than or equal to 0.324) apparently impair spermatogenesis.

Adult↗
PubMed1984

Pure monosomy and trisomy 2q24.2----q3105 due to an inv ins(7;2)(q21.2;q3105q24.2) segregating in four generations.

An inv ins(7;2)(q21.2;q3105q24.2) was found to segregate through four generations of a family. Adjacent-1 segregation aneusomies were ascertained in five patients: three monosomics and two trisomics; and the corresponding syndromes were delineated. The comparative analysis between these and other previously described 2q aneusomic individuals led to the conclusion that a large cleft between first and second toes is a constant feature in monosomy 2q24----q31. No other trait could plausibly be mapped. Risks of 7.9 to 31.6% for aneusomic children and of 26.3% for abortion were estimated in the present family.

Bone and Bones↗
PubMed1984

On telomere replication and fusion in eukaryotes: apropos of a case of 45,X/46,X,ter rea(X;X)(p22.3;p22.3).

A Mexican 181/2-year-old girl with short stature, primary amenorrhea, and mild Turner stigmata was found to have a 45,X/46,X,ter rea(X;X)(p22.3;p22.3) karyotype in her lymphocytes. The rearranged chromosome was twice the size of a normal X, appeared to be attached head-to-head, had no detectable chromatin loss, only one primary constriction, constitutive heterochromatin at both the centromere and pseudocentromere regions, was mitotically stable, and always showed late replication. From the analysis of this and other X;X terminal rearrangements we draw four conclusions: (1) Terminal rearrangements may arise either by telomeric fusion (tel fus) without loss of genetic material or from a conventional telomeric translocation. (2) Telomeric fusions between homologous chromosomes (the commonest type) can be secondary to impaired telomeric replication. (3) Phenotypically, patients with an X;X terminal rearrangement show great variability which depends mainly on whether or not chromatin has been lost in the rejoining process and a 45,X clone. (4) Patients with an X;X telomeric fusion without mosaicism are likely to have an XXX phenotype, whereas turneroid features are expected in mixoploidies that include an X monosomic clone and in cases of translocations involving the short arms.

Adolescent↗
PubMed1984

De novo del(3)(q2800).

A severely malformed girl who died at 3 months of age was found to have de novo del(3)(q2800). The main features were retarded growth and development, microdolichocephaly, bilateral microphthalmia, bilateral cleft lip and palate, cardiac murmur, clenched hands and long flat feet with flexed toes. The phenotypical comparison with the other three 3q partially monosomic patients so far reported did not allow the individualization of a distinct syndrome.

Abnormalities, Multiple↗
PubMed1984

Tetrasomy 18p: a distinctive syndrome.

A 10-month-old girl with growth and psychomotor retardation and pyramidal signs, was found to have a 47,XX,inv(9)(p11q13),+i(18p) karyotype. Whereas the inverted chromosome was inherited from the father, the isochromosome was of unknown origin. A comparative analysis with 17 similar cases from the literature lead to the conclusion that the tetrasomy 18p actually constitutes a distinctive syndrome.

Adult↗
PubMed1983

Partial trisomy 1q and monosomy 18q due to a de novo t(1;18)(q25;q23).

A two-year-old girl trisomic for the segment 1q25 leads to qter and partially monosomic for band 18q23 as a consequence of a de novo t(1;18)(q25;q23) is reported. Most of the proposita's clinical findings have been described in the 1qter trisomy and some others in the 18q monosomy. This observation is interpreted as additional evidence of epi-, iso-, and hypostatic interactions at the chromosomal level.

Abnormalities, Multiple↗
PubMed1983

"Pure" monosomy 21 pter leads to q21 in a girl born to a couple 46,XX,t(14;21)(p12;q22) and 46,XY,t(5;18)(q32;q22).

A two-year-old girl with a "pure" 21pter leads to q21 monosomy secondary to a 3:1 segregation of a maternal translocation t(14;21)(p12;q22) is described. The father's karyotype was 46,XY,t(5;18)(q32;q22). This observation permits to further delineate the 21q proximal monosomy syndrome and to comment the very rare finding of a couple in which both partners have different reciprocal translocations.

Abnormalities, Multiple↗
PubMed1983

Del (8) (q212q2200) de novo in a boy without Langer-Giedion syndrome.

A two year-old boy with congenital malformations, psychomotor retardation and absence of phenotypical features of the Langer-Giedion syndrome (LGS) was found to have a de novo del (8) (q212q2200). The comparative analysis with other 8q monosomic cases suggests the existence of at least two distinct syndromes: one due to the monosomy of a part of the segment 8q22----q24, clinically manifested as the LGS, and the other to the deletion of the band 8q21.

Abnormalities, Multiple↗
PubMed1982

Tetrasomy 9p: clinical aspects and enzymatic gene dosage expression.

A girl aged 13 years and 9 months with a phenotypic appearance of 9p trisomy was studied. Chromosome analysis of peripheral blood lymphocytes revealed a 9p tetrasomy [47,XX,+i(9p)] with no evidence of mosaicism. Biochemical studies corroborate the gene dosage effect for galactose-1-phosphate uridyltransferase. The roentgenological findings were quite similar to those of the 9p trisomy except for hypoplastic and angulated ribs, and malformed vertebral bodies, which are probably exclusive of the tetrasomic state.

Adolescent↗
PubMed1981

Retinoblastoma-del(13q14): report of two patients, one with a trisomic sib due to maternal insertion. Gene-dosage effect for esterase D.

Two cases of del(13)-retinoblastoma are reported. Case 1, a 13-month-old male, was monosomic due to the malsegregation of the maternal ins(20;13)(p12;q1307q14.3). The patients's sister was trisomic for 13q1307q14.3 with no evident phenotypic effect. Case 2 was a 20-month-old female with a denovo del(13)(q1303q14.3). In both instances esterase D activity showed a remarkable gene-dosage effect in monosomy, disomy, and trisomy, thus confirming the assignment of the gene locus to 13q14, and more precisely to the proximal half of this band. In all instances, the ESTD phenotypes were 1-1. It is suggested that esterase D activity should become an important diagnostic criteria for the various etiological forms of retinoblastoma.

Carboxylesterase↗