Biomedical subjects

T R Wang

Publications and source records attributed to T R Wang.

At least 55 records · Page 3Linked to original sources

PubMed1996

Metabolic function and liver histopathology in Reye-like illnesses.

Forty children with Reye syndrome (RS) or Reye-like illnesses were investigated to elucidate the underlying aetiologies. Extensive biochemical studies including patterns of organic acids and amino acids, liver histopathology, and, if available, a DNA approach were performed. In addition to classical RS (n = 10), the causes of Reye-like conditions included hereditary organic acidaemias (n = 13), urea cycle defects (n = 4), mitochondrial disorders (n = 3), fulminant hepatitis (n = 2), tyrosinaemia (n = 1), valproate-associated hepatotoxicity (n = 1), and other non-specific generalized organic acid disorders (n = 6). It is important to collect specimens when encephalopathy with liver dysfunction of unknown causes is noted. When the underlying inherited metabolic disorders are confirmed, the prevention of the recurrence by adequate diet control and medications, and genetic counselling become possible.

Acidosis↗

PubMed1996

Amelia, dextrocardia, asplenia, and congenital short bowel in deleted ring chromosome 4.

We report a female baby with multiple congenital anomalies including left upper amelia, congenital short bowel with malrotation and pseudo-obstruction, dextrocardia with situs solitus, patent ductus arteriosus, and a tiny atrophic spleen. Chromosome study showed de novo 46,XX/46,XX,-4, + r(4)(p16-->q22.3)/47,XX,4, + r(4) (p16-->q22.3), + del(4)(pter-->q22.3:). The clinical findings in the patient were probably caused by the interaction of partial trisomy 4pter-->q22.3 or 4p16-->q22.3 and partial monosomy of 4q22.3-->4qter. This karyotype and phenotype have not previously been reported.

Abnormalities, Multiple↗

PubMed1996

High frequency of two mutations in codon 778 in exon 8 of the ATP7B gene in Taiwanese families with Wilson disease.

The gene for Wilson disease (WD) has been cloned as a P type copper transporter gene (ATP7B). To elucidate the possible genetic mechanism for the diversity of clinical manifestations, we characterised 22 Taiwanese families with WD by microsatellite haplotyping of close DNA markers D13S314-D13S301-D13S316. We also screened for mutations of codon 778 in the transmembrane region. There were at least 15 haplotypes within eight broad subgroups observed among 44 WD chromosomes. Among the 22 unrelated patients, we found that six patients (27%) carried a codon 778 mutation. Nucleotide sequence analysis showed there were two different mutations: the previously reported Arg778Leu mutation in four patients and Arg778Gln, a new mutation, in two patients. The two different mutations of the same codon occurred in two distinct microsatellite haplotypes.

Codon↗

PubMed1996

Kleine-Levin syndrome in a boy with Prader-Willi syndrome.

A 9 1/2-year-old Taiwanese boy with Prader-Willi syndrome had the following characteristics: difficulties with sucking, feeding and hypotonia during infancy, a dysmorphic face (triangular mouth, high arched palate, almond-shaped eyes and large head circumference with a relatively narrow bifrontal diameter), borderline intelligence, hypogonadism, hyperphagia, skin picking and truncal obesity. The boy experienced two hypersomnia episodes, at age 8 and 9 years, with both episodes lasting for 10 days. During the two episodes, he was found to have an exacerbated case of hyperphagia, pica, poor emotional control, stereotyped speech and agitated behavior upon awakening. After each episode, the boy had complete remission. Our findings show that the two episodes are compatible with Kleine-Levin syndrome. The relationship between the two syndromes, the Prader-Willi syndrome and the Kleine-Levin syndrome, deserves further study.

Child↗

PubMed1996

Prader-Willi syndrome: clinical and molecular cytogenetic investigations.

Prader-Willi syndrome is characterized by hypotonia and feeding difficulties in the neonatal period, with the childhood development of hyperphagia leading to obesity, developmental delay, hypogonadism, short stature and small hands and feet. Correct diagnosis of Prader-Willi syndrome is important because of its clinical implications and the need for family genetic counseling. In order to determine the most efficient method of diagnosing the condition, we evaluated 37 patients with a putative diagnosis of Prader-Willi syndrome by both clinical and molecular cytogenetic analyses. Clinical evaluation showed that 25 patients fulfilled the diagnostic criteria for Prader-Willi syndrome. A deletion of the region 15q11.2-13 was cytogenetically identified in 20 patients using a high-resolution technique. Four additional cases were detected by fluorescence in situ hybridization (FISH) with the cosmid probes for D15S11, r-aminobutyric acid receptor beta 3 (GABRB3), small nuclear ribonucleoprotein-associated peptide N (SNRPN) or D15S10 (Prader-Willi/ Angelman syndrome region probes). The deletion of SNRPN was documented in 24 Prader-Willi syndrome patients. Only one additional patient with typical Prader-Willi syndrome features did not have any deletion over 15q11-13 at either the cytogenetic or molecular level. FISH provides a more reliable method than high-resolution chromosome analysis for the diagnosis of Prader-Willi syndrome. Associated conditions such as hypopigmentation, small-joint laxity, arachnodactyly, seizure disorder, optic atrophy, congenital heart disease, Perthes' disease, hirsutism, astigmatism/amblyopia, microcephaly and neuropsychiatric disturbances dictate the effects of a contiguous gene syndrome. Morbidity is high among patients with obesity and associated conditions. Appropriate genetic counseling should be given to the parents and dietary management should be helpful for patients with Prader-Willi syndrome.

Adolescent↗

PubMed1996

Chromosomal rearrangements detected by FISH and G-banding.

Fluorescence in situ hybridization (FISH) using chromosome-specific DNA libraries as painting probes, locus-specific unique sequence (cosmid) probes, and Y-specific repetitive sequences was applied in the analysis of eighteen cases of chromosomal rearrangements of undetermined nature. FISH clarified the origin of the extra or translocated chromosome segments in seventeen patients, one with 2q+, two with 4q+, one each with 6p+, 7p+, 9q+, 10p+, 11q+ and 12p+, two with 13q+, and one each with 15q+, 17p+, 18p+, 20p+, 21p+ and Yq+, as well as the nature of a de novo supernumerary chromosome marker in a previously reported case. By G-banding and molecular cytogenetic studies of the family members, six cases were determined to have unbalanced translocations inherited from the carrier parent. The extra translocated genetic material may cause specific trisomic syndromes, including partial 6p21.3-p23, 9q32-q34.3, 13q32-q34, 15q24-q26, and 17p11.2-p13 trisomies in those patients. A translocated 21q segment on 12p was shown by a painting probe in a patient with Down features. A patient with cat cry syndrome resulting from a loss of the terminal segment of the short arm of chromosome 5 was confirmed by a cosmid probe showing de novo reciprocal translocation between chromosomes 5 and 18:t(5;18) (p13.3;p11.31). With FISH, the extra material on the rearranged chromosome could also be identified as duplicated or translocated. The FISH technique thus provides a method for the analysis of extra structurally abnormal chromosomes (especially in de novo cases), recognizable syndromes (contiguous gene syndromes) caused by translocated deletion from parental balanced chromosome rearrangements, and supernumerary marker chromosomes. FISH subsequent to G-banding is also of great help in the confirmation of preliminary abnormal G-banded karyotypes after a modified destaining procedure. In conclusion, the combination of G-banding and FISH is very useful in the accurate diagnosis of chromosomal rearrangements.

Chromosome Aberrations↗

PubMed1996

Cytochrome c oxidase deficiency in fibroblasts of a patient with mitochondrial encephalomyopathy.

Cytochrome c oxidase (CCO) deficiency is associated with various types of mitochondrial encephalomyopathy. The enzyme activities in different tissues and organs are varied. We report an 11-year-old girl with CCO deficiency, who presented with nystagmus, ptosis and optic atrophy. Her younger sister died of respiratory failure at 7 years of age and had the same initial clinical manifestations. Their parents were consanguineous. The girl had mild mental retardation and frequent premature ventricular contractions. Brain magnetic resonance imaging of the patient on admission revealed multiple lesions in both the gray and white matter. Except for arrhythmia and marked right axis deviation of the heart on electrocardiography, no other evidence of cardiac involvement was noted. Although a muscle biopsy was normal for both histochemical stains and electron microscopy, the enzyme assays in cultured skin fibroblasts revealed partial CCO deficiency, which may explain the clinical presentations.

Arrhythmias, Cardiac↗

PubMed1996

Double aneuploidy with Down's-Klinefelter's syndrome.

The occurrence of double aneuploidy, ie, the existence of two chromosomal abnormalities in the same individual, is a relatively rare phenomenon. A 1-year-old boy with Down's syndrome resulting from de novo mosaic 21 trisomy with an additional X in the karyotype: 47,XXY/48,XXY,+21 (4%/96%) is reported. Besides the typical features of Down's syndrome, the patient did not have the commonly associated conditions (recurrent respiratory tract infections, congenital heart disease, thyroid or digestive tract problems). A molecular cytogenetic method with biotin-labeled probe D13Z1/D21Z1 was used to confirm the diagnosis and to clarify the status of Down's syndrome mosaicism which explained the milder stigmata of Down's syndrome in this case. The coexistence of Klinefelter's syndrome (47,XXY) also may have contributed to the development of normal height and micropenis in this patient. To our knowledge, this is the first case of Down's syndrome together with Klinefelter's syndrome in Taiwan.

Aneuploidy↗

PubMed1996

Amino acid and DNA analyses in a family with ornithine transcarbamylase deficiency.

Ornithine transcarbamylase (OTC) is a hepatic mitochondrial enzyme involved in the detoxification of ammonia by the urea cycle. OTC deficiency is an X-linked genetic disorder, usually causing neonatal or infantile hyperammonemia, coma and death. We attended a male newborn who had poor feeding since 30 hours of age, at which time, he then rapidly progressed to a comatose state. Hyperammonemia and liver dysfunction were noted. Analysis of plasma amino acids showed elevated levels of glutamine and alanine, but a decreased level of arginine and no citrulline. OTC deficiency was diagnosed by family history of early death of newborn males on the maternal side and characteristic biochemical findings. In addition, it was proved by Southern blot analysis of genomic DNA. Although OTC deficiency has been described as the most common inborn error of ureagenesis in humans, to our knowledge, this is the first report in a Chinese family confirmed by biochemical and DNA analyses.

Amino Acid Metabolism, Inborn Errors↗

PubMed1996

Hepatoblastoma in an infant with Beckwith-Wiedemann Syndrome.

A 3-month-old Chinese male infant with typical manifestations of Beckwith-Wiedemann Syndrome (BWS), such as macroglossia, hepatomegaly, umbilical hernia and hypoglycemia, presented with a large hepatic tumor. The tumor measured 7.6 x 8.0 x 7.5 cm. An open biopsy of the tumor revealed hepatoblastoma. The family refused chemotherapy, so only supportive care was given. The tumor grew very rapidly and the infant died 17 days after admission due to respiratory failure. To our knowledge, this is the first report of BWS associated with hepatoblastoma in a Chinese infant. This patient was a typical example of the association of BWS and hepatoblastoma, and the possible effect of growth factors on the rapid proliferation of the neoplasm in BWS.

Beckwith-Wiedemann Syndrome↗

PubMed1995

Galloway-Mowat syndrome in Taiwan.

We report on two Chinese female infants with multiple congenital anomalies: microcephaly, apparent porencephaly or encephalomalacia, developmental delay, minor facial anomalies, and contractural arachnodactyly. In the first patient, focal glomerulosclerosis was diagnosed histologically by percutaneous renal biopsy due to proteinuria with hematuria. Congenital hypothyroidism presenting with markedly low T3 and T4 was also noted. She died at age 5 months. The second patient had a very similar condition but less severe brain and kidney malformations. A variant of Galloway-Mowat syndrome is suspected.

Abnormalities, Multiple↗

PubMed1995