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Biomedical subjects

D Chitayat

Publications and source records attributed to D Chitayat.

At least 73 records · Page 4Linked to original sources
PubMed1998

Fetal bilateral subdural haemorrhages. Prenatal diagnosis and spontaneous resolution by time of delivery.

We report a patient diagnosed prenatally on routine fetal ultrasound, at 30 weeks' gestation, with subdural haemorrhage. The mother had suffered a mild abdominal trauma and had Factor XI deficiency; however, both were felt to be aetiologically insignificant. Prenatal follow-up showed a complete resolution of the haematoma and no postnatal sequelae have been noted to date. The aetiologies and outcomes in the few previously reported cases are reviewed and compared with our case.

Adult↗
PubMed1997

Brachydactyly-short stature-hypertension (Bilginturan) syndrome: report on two families.

We report on two families with autosomal dominant brachydactyly of hands and feet and hypertension. All affected members of the first family had proportionate short stature. However, the propositus and the affected relatives in the second family were only short compared to unaffected relatives. The hypertension was medically responsive in all cases. The propositus in the second family had poor compliance and a striking generalized vasculopathy. All patients were of normal intelligence and had a normal facial appearance. The brachydactyly-short stature-hypertension syndrome was first reported by Bilginturan et al. [1973] in a Turkish family and the families reported by us are Caucasian and Hispanic. The gene causing this condition in the original Turkish family was recently mapped to 12p. Our report expands our existing knowledge and the ethnic diversity of this syndrome.

Adult↗
PubMed1997

Arthrogryposis multiplex congenita, craniofacial, and ophthalmological abnormalities and normal intelligence: a new syndrome?

We report on an 8-year-old boy with clinical manifestations suggestive of a new arthrogryposis syndrome. These included characteristic craniofacial abnormalities, cleft palate, arthrogryposis multiplex congenita, pulmonary hypoplasia, cryptorchidism, and unusual ophthalmological findings. There was no intrauterine growth retardation or decreased fetal movements. Despite the poor prognosis expected in early life, the patient presented with normal mental capability on follow-up. Family data showed that a maternal first cousin of the mother (mother's brother's son) had similar findings and died in infancy. Differential diagnosis included Pena-Shokeir syndrome or phenotype, Gordon syndrome, Marden-Walker syndrome, and the syndrome of arthrogryposis with ophthalmoplegia and retinopathy. The possibility of autosomal dominant inheritance with reduced penetrance is suggested for this apparently new syndrome.

Abnormalities, Multiple↗
PubMed1997

Omphalocele in Miller-Dieker syndrome: expanding the phenotype.

We report on a patient prenatally diagnosed with omphalocele, mild cerebral ventriculomegaly, nuchal fold thickening, and cystic changes in the umbilical cord who was found postnatally to have lissencephaly type I. Prenatal chromosome analysis showed a normal male karyotype; however, postnatal high resolution banding and FISH analysis, using a probe for locus D17S379 in chromosome region 17p13.3, demonstrated a deletion at 17p13.3 consistent with Miller-Dieker syndrome (MDS). A review documented four more cases with MDS/isolated lissencephaly/17p-, with omphalocele. Because MDS is a contiguous gene disorder, we speculate that a gene or genes in this region have a major role in the closure of the lateral folds or the return of the midgut from the body stalk to the abdomen at 5-11 weeks of gestation. Prenatal diagnosis of omphalocele with mild ventriculomegaly should prompt FISH analysis for a deletion in 17p13.3.

Abnormalities, Multiple↗
PubMed1997

Limb defects in homozygous alpha-thalassemia: report of three cases.

Homozygosity for the South-Asian alpha-thalassemia (--SEA/) deletion is a serious hematological condition that results, in most cases, in intrauterine or postnatal death due to anemia and severe hypoxia of prenatal onset. A relationship between congenital abnormalities and intra-uterine hypoxia has been postulated. However, since homozygosity for the (--SEA/) deletion is most common in underdeveloped countries where detailed autopsies are lacking, the incidence of congenital abnormalities among these babies has not been well delineated. We report on three newborn infants, homozygous for the (--SEA/) deletion, who were born with limb defects. We postulate that this combination is the result of prenatal hypoxia which may affect other fetal body organs. This should be taken into consideration when prenatal treatment of affected fetuses, with intrauterine blood transfusion, is suggested.

Adult↗
PubMed1997

Findings in children exposed in utero to phenytoin and carbamazepine monotherapy: independent effects of epilepsy and medications.

Our objective was to evaluate the patterns of malformations in children exposed in utero to phenytoin (DPH) and carbamazepine (CBZ) monotherapy, and to compare them prospectively with matched mother-child pairs exposed to nonteratogens, and to separate the effects of antiepileptic drugs (AEDs) from those of epilepsy by collecting groups of untreated epileptics and those treated with DPH and CBZ for conditions other than epilepsy. This was a prospective, controlled, and blinded observational study. Thirty-six mother-child pairs exposed to CBZ monotherapy, 34 pairs exposed to DPH monotherapy, and 9 nonmedicated epileptic women and their children were compared with matched mother-child pairs exposed to nonteratogens. The control mothers were matched for maternal age, time of consultation, obstetric history, and socioeconomic status (SES). One main outcome measures a "blinded" morphological assessment of the offspring. We found that minor anomalies were significantly more common among children of epileptics on either drug (P = 0.01) and among DPH-treated nonepileptic offspring (P = 0.03). Among epileptics, the relative risk for minor anomalies following DPH (2.1) was similar to that after exposure to either DPH (P = 0.006) or CBZ (P = 0.01). Increased rates of hypertelorism were detected among DPH-exposed offspring. High forehead, frontal bossing, malar hypoplasia, epicanthus and micrognathia were associated with untreated epilepsy, as well as with DPH and CBZ treatment.

Adult↗
PubMed1997

A new mutation in the type II hair cortex keratin hHb1 involved in the inherited hair disorder monilethrix.

Monilethrix is a rare dominant hair disease characterized by beaded or moniliform hair which results from the periodic thinning of the hair shaft and shows a high propensity to excess weathering and fracturing. Several cases of monilethrix have been linked to the type II keratin gene cluster on chromosome 12q13 and causative heterozygous mutations of a highly conserved glutamic acid residue (Glu 410 Lys and Glu 410 Asp) in the helix termination motif of the type II hair keratin hHb6 have recently been identified in monilethrix patients of two unrelated families. In the present study, we have investigated two further unrelated monilethrix families as well as a single case. Affected members of one family and the single patient exhibited the prevalent hHb6 Glu 410 Lys mutation. In the second family, we identified in affected individuals a lysine substitution of the corresponding glutamic acid residue, Glu 403, in the type II hair keratin hHb1, suggesting that this site represents a mutational hotspot in these highly related type II hair keratins. Both hHb1 and hHb6 are largely coexpressed in cortical trichocytes of the hair shaft. This indicates that monilethrix is a disease of the hair cortex.

Amino Acid Sequence↗
PubMed1996

Tissue-specific methylation differences and cognitive function in fragile X premutation females.

Tissue-specific variation in (CGG)n repeat size and methylation status of the FMR1 gene was investigated in 17 female premutation carriers. Minor variation in premutation repeat size among leukocyte, lymphoblast, and fibroblast tissues was noted in some subjects. One subject exhibited a premutation size allele of (CGG)64 in leukocyte and fibroblast tissues by polymerase chain reaction analysis but a normal-size allele of (CGG)46 in lymphoblast cells, suggesting low-level mosaicism in blood and clonality of the lymphoblast cell line. Six subjects exhibited differences in methylation pattern between leukocytes and lymphoblasts but not between leukocytes and fibroblasts, whereas 2 subjects showed large differences in methylation pattern between leukocytes and fibroblasts. Cognitive function was studied in 14 subjects using the Wechsler Adult Intelligence Scale-Revised. Mean Verbal and Performance IQs were well within the average range as was the mean Full Scale IQ; nevertheless, a trend toward lower Performance IQ compared with Verbal IQ was observed. No significant correlation was apparent between Full Scale IQ and (CGG)n repeat size; however, a significant positive correlation was observed between Full Scale IQ and the proportion of the active X carrying the normal FMR1 allele in fibroblasts but not in leukocytes or lymphoblasts.

Adult↗
PubMed1996

The expanding clinical phenotype of the tRNA(Leu(UUR)) A-->G mutation at np 3243 of mitochondrial DNA: diabetic embryopathy associated with mitochondrial cytopathy.

We describe a family which demonstrates and expands the extreme clinical variability now known to be associated with the A-->G transition at nucleotide position 3243 of the mitochondrial DNA. The propositus presented at birth with clinical manifestations consistent with diabetic embryopathy including anal atresia, caudal dysgenesis, and multicystic dysplastic kidneys. His co-twin was normal at birth, but at 3 months of life, presented with intractable seizures later associated with developmental delay. The twins' mother developed diabetes mellitus type I at the age of 20 years and gastrointestinal problems at 22 years. Since age 19 years, the maternal aunt has had recurrent strokes, seizures, mental deterioration and deafness, later diagnosed as MELAS syndrome due to the tRNA(Leu(UUR)) A-->G mutation. A maternal uncle had diabetes mellitus type I, deafness, and normal intellect, and died at 35 years after recurrent strokes. This pedigree expands the known clinical phenotype associated with tRNA(Leu(UUR)) A-->G mutation and raises the possibility that, in some cases, diabetic embryopathy may be due to a mitochondrial cytopathy that affects both the mother's pancreas (and results in diabetes mellitus and the metabolic dysfunction associated with it) and the embryonic/fetal and placental tissues which make the embryo more vulnerable to this insult.

Abnormalities, Multiple↗
PubMed1996

FISH detection of chromosome 15 deletions in Prader-Willi and Angelman syndromes.

We have evaluated fluorescence in situ hybridization (FISH) analysis for the clinical laboratory detection of the 15q11-q13 deletion seen in Prader-Willi syndrome (PWS) and Angelman syndrome (AS) using probes for loci D15S11, SNRPN, D15S10, and GABRB3. In a series of 118 samples from patients referred for PWS or AS, 29 had deletions by FISH analysis. These included two brothers with a paternally transmitted deletion detectable with the probe for SNRPN only. G-banding analysis was less sensitive for deletion detection but useful in demonstrating other cytogenetic alterations in four cases. Methylation and CA-repeat analyses of 15q11-q13 were used to validate the FISH results. Clinical findings of patients with deletions were variable, ranging from newborns with hypotonia as the only presenting feature to children who were classically affected. We conclude that FISH analysis is a rapid and reliable method for detection of deletions within 15q11-q13 and whenever a deletion is found, FISH analysis of parental chromosomes should also be considered.

Angelman Syndrome↗
PubMed1996

Terminal deletion of the long arm of chromosome 3 [46,XX,del(3)(q27-->qter)].

We report on a terminal deletion of the long arm of chromosome 3 [46,XX,del(3)(q27-->qter)] in a female newborn infant who died 45 hours after delivery and had multiple congenital abnormalities including bilateral anophthalmia, congenital heart disease, and abnormal genitalia. The findings are compared to those of four previously reported cases with terminal del (3q).

Abnormalities, Multiple↗
PubMed1996

Limits of clinical assessment in the accurate diagnosis of Machado-Joseph disease.

BACKGROUND: Machado-Joseph disease (MJD) is a type of autosomal dominant spinocerebellar ataxia for which molecular diagnosis is available. We identified 4 families segregating the MJD mutation in which no unequivocal clinical diagnosis could be established prior to molecular testing. Ethnic background, clinical, and molecular characteristics of 19 individuals carrying the MJD mutation in these 4 families were compared with a group of 32 Portuguese families who were clinically diagnosed as having MJD and were found to carry the MJD mutation. RESULTS: Several factors seemed to have an impact in the accuracy of the clinical diagnosis, such as ethnic origin; the number of affected individuals available for examination in each family; the absence of patients showing specific clinical features, such as extrapyramidal signs; and the size of the expanded CAG repeat in the MJD gene. CONCLUSION: Since the recognition of MJD based solely on clinical grounds might sometimes be misleading, a search for the MJD mutation should be performed in patients with a clinical diagnosis of spinocerebellar degeneration.

Adult↗
PubMed1996

Abnormalities of the intra-abdominal fetal umbilical vein: reports of four cases and a review of the literature.

Anomalies of the fetal umbilical vessels are rare, excepting single umbilical arteries which occur in 0.2-1.0% of pregnancies. Abnormalities of the intra-abdominal umbilical vein may be categorized into three main groups: (1) the ductus venosus is patient but the right umbilical vein persists; (2) the ductus venosus is not patent, and there is extrahepatic continuation of the umbilical vein; and (3) the umbilical vein takes a normal course but is abnormally dilated. We describe cases of each of these types of anomaly, including the first report of prenatal diagnosis of insertion of the umbilical vein into the iliac vein, and review the literature on this subject.

Adolescent↗
PubMed1996

Linkage analysis of two Canadian families segregating for X linked spondyloepiphyseal dysplasia.

X linked spondyloepiphyseal dysplasia (SED) is caused by a growth defect of the vertebral bodies leading to characteristic changes in the vertebral bodies and a short trunk. The gene responsible for this disorder has previously been mapped to Xp22, with a maximum likelihood location between markers DXS16 and DXS92. We present linkage data using microsatellite markers on two Canadian X linked SED families, one of Norwegian descent and the other from Great Britain. In the Xp22 region, three recombination events have occurred in these families, two between markers DXS996 and DXS1043 and one between DXS999 and DXS989. One family shows a maximal lod score of 3.0 at theta = 0 with marker DXS1043 and the other family has a maximal lod score of 1.2 at theta = 0 with markers DXS1224 and DXS418. Both families therefore support the previously reported gene localisation.

Canada↗
PubMed1996

Frequency of spinocerebellar ataxia type 1, dentatorubropallidoluysian atrophy, and Machado-Joseph disease mutations in a large group of spinocerebellar ataxia patients.

The spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative disorders varying in both clinical manifestations and mode of inheritance. Six different genes causing autosomal dominant SCA are mapped: SCA1, SCA2, Machado-Joseph disease (MJD)/SCA3, SCA4, SCA5, and dentatorubropallidoluysian atrophy (DRPLA). Expansions of an unstable trinucleotide CAG repeat cause three of these disorders: SCA type 1 (SCA1), MJD, and DRPLA. We determine the frequency of the SCA1, DRPLA, and MJD mutations in a large group of unrelated SCA patients with various patterns of inheritance and different ethnic backgrounds. We studied 92 unrelated SCA patients. The frequency of the SCA1 mutation was 3% in the overall patient group and 10% in the non-Portuguese dominantly inherited SCA subgroup. We found that DRPLA mutation in only one Japanese patient, who was previously diagnosed with this disease. We identified the MJD mutation in 41% of the overall patient group, which included 38 autosomal dominant kindreds of Portuguese origin; the frequency of the MJD mutation among the non-Portuguese dominantly inherited cases was 17%. These results suggest that SCA may be occasionally caused by the SCA1 mutation and rarely caused by the DRPLA mutation and that, to date, the MJD mutation seems to be the most common cause of dominantly inherited SCA. Finally, our results suggest that recessively inherited cases of SCA are not caused by the known trinucleotide repeat expansions.

Brain Chemistry↗