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R H Smythe

Publications and source records attributed to R H Smythe.

At least 19 recordsLinked to original sources
PubMed1994

Partial trisomy for 2q in a patient with dir dup(2) (q33.1q35).

A 22 year old woman with partial trisomy for the long arm of chromosome 2 is described. The karyotype is 46,XX, dir dup(2)(q33.1q35) de novo confirmed by FISH using a chromosome 2 specific paint. Parental chromosome studies were normal. To our knowledge this is the first report of trisomy for this specific segment of 2q and only the sixth case of de novo direct duplication of 2q, one of which was mosaic. Clinical features include epicanthus, clinodactyly, scoliosis, broad, flat nasal bridge, thin upper lip, long philtrum, and short neck.

Abnormalities, Multiple↗
PubMed1990

Three cases of partial trisomy 7q owing to rare structural rearrangements of chromosome 7.

Three cases of partial trisomy 7q are described. One case had duplication of region 7q22.1----q31.2 owing to a de novo direct intra-arm intrachromosomal duplication. The other two cases, first cousins, were trisomic for 7q34----qter, resulting from recombination within the inserted segment of a dir ins(7;17)(q34;q23.1q25.3)mat. All three cases had a number of the already recorded manifestations of partial trisomy 7q, namely strabismus, low set ears, depressed nasal bridge, small nose, hypotonia, and mental retardation.

Adult↗
PubMed1990

Partial monosomy for chromosome 22 in a patient with del(22)(pter----q13.1::q13.33----qter).

An 18 month old girl with partial monosomy for the long arm of chromosome 22 is described. The karyotype was 46,XX,del(22)(pter----q13.1::q13.33----qter). To our knowledge this is the first report of monosomy for this specific segment of chromosome 22. Clinical features include developmental delay in all areas, hypotonia, macrosomia, full cheeks, eyebrows, and eyelids, mild epicanthus, wide nasal bridge, long philtrum, and thick lower lip. Parental chromosome studies were normal.

Chromosome Aberrations↗
PubMed1989

Familial distal trisomy 8(q24.13----qter).

Trisomy for the distal part of the long arm of chromosome 8(q24.13----qter) is described in three sibs. The anomaly arose as an adjacent 1 meiotic segregation from a balanced reciprocal translocation t(1;8)(q44; q24.13)mat.

Adult↗
PubMed1987

Partial monosomy 12p13.1----13.3.

We describe a 27 month old female child with partial monosomy for the short arm of chromosome 12: 46,XX,del(12)(p13.1----p13.3). She differs from the eight cases described by others, in that she is less severely affected. Her main clinical features are developmental delay, protruding tongue, strabismus, slightly unusual facies, slight micrognathia, and speech delay.

Child, Preschool↗
PubMed1986

Studies on three rare fragile sites. 2q13, 12q13, and 17p12 segregating in one family.

Three fragile sites 2q13, 12q13, and 17p12 were found in one family. In the index case, who was first investigated in 1969 for low birth weight and bilateral inguinal hernia, three tissues were examined, blood, marrow, and skin. Three of the family have been reinvestigated after 17 years. Cultures for sister chromatid exchange (SCE) and the effects of aphidicolin, fluorodeoxyuridine (FUdR), bromodeoxyuridine (BrdU), and methotrexate on the frequency of the fragilities were studied. The mother of the index case who is an obligate carrier for the fragile 2q13 does not express it in folate/thymidine deficient medium. Further studies on her using a lymphoblastoid cell line, showed that there was a reduced level of fragility of 12q13 and 17p12 in B-lymphocytes compared to T-lymphocytes. Excess thymidine and FUdR when added to the lymphoblastoid cell line did not induce the 2q13. These studies also confirm the induction of a range of common fragile sites by treatment with aphidicolin, showing in addition homozygosity for at least 3p14, 6q26, 16q23, and Xp22. There were no detectable increases in the SCE rate between individuals with fragile sites and the five controls tested. There was no history of cancer or phenotypic abnormalities in the family.

Adolescent↗
PubMed1985

A complex structural rearrangement of chromosome 4 in a woman without phenotypic features of Wolf-Hirschhorn syndrome.

A 32-year-old mentally retarded woman was found to have a complex rearrangement of one chromosome 4. Her karyotype is interpreted as 46,XX,inv(4) (pter----p14::q12----p14::q12----qter) del (4) (pter----15.33::p15.2----qter). Clinically she does not show the features of the Wolf-Hirschhorn syndrome. Her phenotype and cytogenetic findings are compared with 2 other reported cases of 4p-without Wolf-Hirschhorn syndrome.

Adult↗
PubMed1983

Familial paracentric inversion of 1p.

We report a paracentric inversion of 1p in a boy with mild mental retardation. The chromosome aberration was identified by high resolution chromosome banding, and was also present in his phenotypically normal mother and other relatives. The boy's karyotype was considered to be 46,XY,inv(1) (p31,2p36.22) ISCN (1981).

Child, Preschool↗
PubMed1983

Two cases of ring chromosome 11.

Two cases of ring chromosome 11 are reported. Both had mental retardation, microcephaly, and short stature. High resolution G banding in case 1 showed no visible loss of chromatin, the karyotype being assessed as 46,XX,r(11) (p15 X 4q2 X 5). In case 2, a Wilm's tumour developed at 8 months and the child died at 18 months. Cytogenetic analysis by Q banding demonstrated minimal chromosome deletion and the karyotype was considered to be 46,XY,r(11) (p15q25).

Abnormalities, Multiple↗
PubMed1983

Partial trisomy 14q24 leads to qter.

A newborn male with partial trisomy for the distal part of the long arm of chromosome 14 (14q24 leads to qter) is described. The anomaly arose as an adjacent 1 meiotic segregation product from a balanced translocation t(11;14) (q25;q24) in the mother (figure). To our knowledge only one previous case involving the same segment has been reported. The karyotype was confirmed as 46,XY,der(11),t(11;14)(q25;q24) mat.

Chromosomes, Human, 13-15↗
PubMed1982

Cd branding studies in a homologous Robertsonian 13;13 translocation.

A phenotypically normal female with a history of two miscarriages was found to have the karyotype 45,XX,t(13p:13p). C banding showed the translocation to have two regions of centromeric constitutive heterochromatin, silver staining showed an active NOR in 60% of the cells screened, and Cd banding studies showed a single Cd band with absence of the Cd band at the suppressed centromere.

Chromosome Banding↗
PubMed1979

Discovery of an inherited bisatellited metacentric microchromosome in amniotic cell culture.

The identification is reported of an extra bisatellited metacentric microchromosome in amniotic cell culture from the third pregnancy of an identical twin (amniocentesis being performed because of age), and its subsequent finding in the maternal parent as an inherited familial marker. The carriers of the microchromosome are all clinically normal and the parents opted for continuation of pregnancy. Only one other report was found in the literature of a similar microchromosome detected in amniotic fluid culture, but we believe ours to be the first bisatellited microchromosome to be clearly identified from an amniotic cell culture using silver staining.

Adult↗