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Biomedical subjects

H Tonoki

Publications and source records attributed to H Tonoki.

63 records · Page 4Linked to original sources
PubMed1991

Regional mapping of the parathyroid hormone gene (PTH) by cytogenetic and molecular studies.

The locus for the human parathyroid hormone gene (PTH) was assigned to a region proximal to 11p15.4 using restriction fragment length polymorphisms and gene dose studies performed on a patient with the Beckwith-Wiedemann syndrome accompanied with a chromosome abnormality [46,XX,-14,+der(14),t(14;11)(q32.3;p15.3)pat]. Our data suggest that PTH is localized in 11p15.3----p15.1, most likely near the border of the bands 11p15.4 and 11p15.3.

Beckwith-Wiedemann Syndrome↗
PubMed1990

A new syndrome of dwarfism, brachydactyly, nail dysplasia, and mental retardation in sibs.

We describe a new multiple congenital anomaly/mental retardation (MCA/MR) syndrome in chromosomally normal sibs. Both had microcephaly, a "coarse" face with synophrys, ear anomalies, type B brachydactyly, nail dysplasia, skeletal anomalies, dwarfism, and mental retardation. Their mother had nail dysplasia, mild mental retardation, and short stature. An uncle, a younger brother of the mother, died at 17 years of age and also had a "coarse" face, digital anomalies, dwarfism, and severe mental retardation. The malformation complex in this family apparently has not been described previously, and the manifestations of the patients do not correspond to those of any known malformation syndrome. The disorder may be attributable to the pleiotropic effect of an autosomal dominant or an X-linked semidominant gene.

Abnormalities, Multiple↗
PubMed1989

Waardenburg syndrome type I in a child with de novo inversion (2)(q35q37.3).

We report on a child with Waardenburg syndrome type I and a paracentric inversion of chromosome 2. This 20 month-old boy has dystopia canthorum, sensorineural deafness, heterochromia iridis, partially albinotic ocular fundi, and partial leukodermia. He does not have mental retardation or any skeletal abnormalities. Family history was unremarkable. Cytogenetic studies demonstrated that the patient has a paracentric inversion (2)(q35q37.3); his parents have normal chromosomes. These findings suggest that the locus of the gene for Waardenburg syndrome type I may be at 2q35 or 2q37.3.

Abnormalities, Multiple↗
PubMed1988

Cryptomicrotia and short, stubby fingers with excess fingertip arch patterns in a mother and son.

We describe a malformation syndrome of bilateral cryptomicrotia, brachytelomesophalangy, hypoplastic toe nails, and excess fingertip arch patterns in a chromosomally and mentally normal mother and son. Familial occurrence of this malformation complex has not been described previously and the manifestations of the patients do not correspond to those of any known malformation syndromes. The disorder in this family may be attributable to the pleiotropic effect of an autosomal or an X-linked dominant gene.

Abnormalities, Multiple↗
PubMed1988

Kabuki make-up (Niikawa-Kuroki) syndrome: a study of 62 patients.

These 62 patients with the Kabuki make-up syndrome (KMS) were collected in a collaborative study among 33 institutions and analyzed clinically, cytogenetically, and epidemiologically to delineate the phenotypic spectrum of KMS and to learn about its cause. Among various manifestations observed, most patients had the following five cardinal manifestations: 1) a peculiar face (100%) characterized by eversion of the lower lateral eyelid; arched eyebrows, with sparse or dispersed lateral one-third; a depressed nasal tip; and prominent ears; 2) skeletal anomalies (92%), including brachydactyly V and a deformed spinal column, with or without sagittal cleft vertebrae; 3) dermatoglyphic abnormalities (93%), including increased digital ulnar loop and hypothenar loop patterns, absence of the digital triradius c and/or d, and presence of fingertip pads; 4) mild to moderate mental retardation (92%); and 5) postnatal growth deficiency (83%). Thus the core of the phenotypic spectrum of KMS is rather narrow and clearly defined. Many other inconsistent anomalies were observed. Important among them were early breast development in infant girls (23%), and congenital heart defects (31%), such as a single ventricle with a common atrium, ventricular septal defect, atrial septal defect, tetralogy of Fallot, coarctation of aorta, patent ductus arteriosus, aneurysm of aorta, transposition of great vessels, and right bundle branch block. Of the 62 KMS patients, 58 were Japanese, an indication that the syndrome is fairly common in Japan. It was estimated that its prevalence in Japanese newborn infants is 1/32,000. All the KMS cases in this study were sporadic, the sex ratio was even, there was no correlation with birth order, the consanguinity rate among the parents was not high, and no incriminated agent was found that was taken by the mothers during early pregnancy. Three of the 62 patients had a Y chromosome abnormality involving a possible common breakpoint (Yp11.2). This could indicate another possibility, i.e., that the KMS gene is on Yp11.2 and that the disease is pseudoautosomal dominant. These findings are compatible with an autosomal dominant disorder in which every patient represents a fresh mutation. The mutation rate was calculated at 15.6 X 10(6).

Abnormalities, Multiple↗
PubMed1988

Origin of the extra chromosome in trisomy 18. A study on five patients using a restriction fragment length polymorphism.

The parental origin of an extra chromosome in five patients with trisomy 18 was traced using a restriction fragment length polymorphism (RFLP) of the human prealbumin (PA) gene, localized to 18p11.1-q12.1, as a genetic marker. MspI digests of the genomic DNAs of the five patients, their parents and normal controls were hybridized with the PA-cDNA. Densitometric analysis on the gene dose of the polymorphic fragments of these patients revealed that three had originated from a maternal meiotic error. The other two patients were uninformative for the parental origin of trisomy 18. Our results indicate that nondisjunctional errors leading to trisomy 18 may occur predominantly at the maternal meiosis, consistent with the results of previous studies on the parental origin of trisomies 21 and 13.

Chromosomes, Human, Pair 18↗
PubMed1986

The Wiedemann-Beckwith syndrome: pedigree studies on five families with evidence for autosomal dominant inheritance with variable expressivity.

We describe 18 individuals from five unrelated families with various manifestations of the Wiedemann-Beckwith syndrome. Pedigree analysis was performed on the 5 families and on another 19 families in the literature, each of which included more than one affected person. The following findings were obtained: 1) the clinical manifestations among the affected individuals were highly variable--those obvious in infancy tended to become less distinct with increasing age; 2) the syndrome was transmitted directly and vertically through three generations in four families, and through two generations in seven families; 3) male-to-male transmission was noted once; 4) the sex ratio in the affected individuals was not significantly different from 1; 5) the segregation ratio of the trait among the sibs of the probands was 0.571 +/- 0.066; 6) the affected + carrier/normal ratio was one among the offspring of the affected individuals and obligate carriers; 7) phenotrance (the expected presence of the trait in a generation) of the syndrome in the sibship of probands was complete, whereas that in earlier generations appeared low. The discrepancy is attributable to the lessening of the clinical features with increasing age as well as to a possibly less aggressive search for abnormalities in older generations. These findings indicate that the syndrome is an autosomal dominant trait with variable expressivity. High-resolution chromosome banding analysis in seven affected individuals and their respective parents showed no abnormalities.

Adult↗