PubMed Health⌕ Search

Biomedical subjects

J T Hecht

Publications and source records attributed to J T Hecht.

At least 91 records · Page 5Linked to original sources
PubMed1991

Cleft lip and palate: no evidence of linkage to transforming growth factor alpha.

Recently, an association of a specific transforming growth factor alpha (TGFA) haplotype has been reported to occur in patients with nonsyndromic cleft lip and palate (CLP) who had a positive family history of the disorder. We tested linkage of CLP to TGFA in 12 multiplex families with clefting. TGFA haplotypes were constructed on the basis of three polymorphic restriction sites. No haplotype was associated with CLP, and discordant inheritance of TGFA haplotypes was observed in a single informative family. The log odds (LOD) score was -2.1 at theta = .05. These findings indicate that CLP and TGFA are not tightly linked in these families.

Alleles↗
PubMed1991

Complex segregation analysis of nonsyndromic cleft lip and palate.

This study was undertaken to examine the inheritance pattern of nonsyndromic cleft lip with or without cleft palate (CL/P). Complex segregation analysis using the unified model as in POINTER and the regressive model as in REGD programs were applied to analyze a midwestern U.S. Caucasian population of 79 families ascertained through a proband with CL/F. In REGD, the dominant or codominant Mendelian major locus models of inheritance were the most parsimonious fit. In POINTER, besides the Mendelian major locus model, the multifactorial threshold (MF/T) model and the mixed model were also consistent with the observed data. However, the high heritability parameter of .93 (SD .063) in the MF/T model suggests that any random exogenous factors are unlikely to be the underlying mechanisms, and the mixed model indicates that this high heritability is accounted for by a major dominant locus component. These findings indicate that the best explanation for the etiology of CL/P in this study population is a putative major locus associated with markedly decreased penetrance. Molecular studies may provide further insight into the genetic mechanism underlying CL/P.

Cleft Lip↗
PubMed1990

Neurologic morbidity associated with achondroplasia.

Neurologic morbidity has long been appreciated in adults with achondroplasia and has recently been recognized to be common in children. Neurologic complications result from bony stenosis involving the entire vertebral column and the base of the skull. These complications are reviewed with special attention to the findings in children.

Achondroplasia↗
PubMed1989

Growth of the foramen magnum in achondroplasia.

Foramen magnum growth curves in achondroplasia and in the general population are presented. The achondroplastic foramen magnum is small at birth, and during the first year it has a severely impaired rate of growth especially in the transverse dimension. This markedly diminished growth results not only from abnormal endochondral bone growth but also because of abnormal placement and premature fusion of the synchondroses. Evaluation of the foramen magnum in achondroplasia should address absolute size of the transverse and sagittal dimensions, shape, and growth centers to determine growth potential of this area.

Achondroplasia↗
PubMed1989

Epilepsy and clefting disorders: lack of evidence of a familial association.

Offspring of women with epilepsy who are taking anticonvulsant medications have an increased incidence of clefting abnormalities. However, there is disagreement as to the extent to which this increase is due to a teratogenic effect of anticonvulsant medications or to a familial association of epilepsy and clefting. Some investigators suggested, but were unable to demonstrate adequately, that clefting and epilepsy associate together in families. In order to address this issue, individuals with a clefting disorder and their relatives were ascertained to determine whether clefting and epilepsy aggregate together in families. The incidence of epilepsy was not increased over that in the general population with a standardized morbidity ratio (SMR) for epilepsy of 0.9 (95% CI 0.2-2.6) for first-degree relatives (excluding parents) and 0.0 for second-degree relatives. The SMRs ranged from 0.7-2.2 for the individual relative types (parents 1.5, sibs 0.7, children 2.2) and were also not increased. These results do not support suggestions that clefting and epilepsy segregate together in families.

Anticonvulsants↗
PubMed1988

Obesity in achondroplasia.

Obesity is a significant and potentially serious health problem in achondroplasia. Body mass indices, weight-to-square of the height ratio (W/H2), and triceps skinfold measurements show that obesity is common. It begins in early childhood and is prevalent at all ages. We recommend that weight be monitored closely in all persons with achondroplasia and that dietary intervention be instituted whenever the body mass indices, W/H2, and triceps skinfold measurements exceed the 95th centile for the general population.

Achondroplasia↗
PubMed1988

Neurological basis of respiratory complications in achondroplasia.

Evaluation of 32 individuals with achondroplasia revealed that 28% had a history of apnea and 22% had respiratory abnormalities on polysomnography. In those patients requiring posterior fossa decompressive surgery, improvement was noted in follow-up polysomnograms. Multimodality studies suggested that brainstem compression was common in achondroplasia and could account in part for the abnormal respiratory function in this disorder, including obstructive apnea, central apnea, and hypoxemia.

Achondroplasia↗
PubMed1987

The Nager syndrome.

The Nager syndrome was identified in a newborn infant and in a subsequent sib by prenatal ultrasonography. This report documents an autosomal recessive pattern of inheritance for this disorder.

Abnormalities, Multiple↗
PubMed1987

Mortality in achondroplasia.

Standardized mortality ratios (SMRs) were determined for a historical cohort of achondroplastic individuals identified through the Medical Genetics Clinics of the University of Texas Health Science Center at Houston and Johns Hopkins Hospital, Baltimore. Mortality was increased at all ages, with an overall SMR of 2.27 (95% confidence interval 1.7-3.0). Sudden death accounted for the excess deaths in those less than 4 years of age, and brain-stem compression was identified as the cause in half of these deaths. Central nervous system and respiratory causes were not significantly increased but accounted for half of the deaths in those 5-24 years of age. SMRs were not significantly increased for those greater than 34 years of age. However, deaths attributed to cardiovascular causes were increased in the 25-54-year-old age group, accounting for 10 of 17 deaths. The overall cardiovascular SMR was 5.2 (95% confidence interval 2.5-9.6). Within this group, severe disability resulting from marked spinal canal stenosis was present in a majority of individuals and may have been a contributing factor in these deaths. This study suggests that the bony abnormalities associated with achondroplasia--i.e., foramen magnum and spinal canal stenosis--may have a significant effect on mortality at all ages but particularly in children. Efforts to minimize these complications are recommended.

Achondroplasia↗
PubMed1986

Foramen magnum stenosis in homozygous achondroplasia.

A 4-month-old female with homozygous achondroplasia and daytime apnea was found to have a small foramen magnum by computerized tomography. Following suboccipital craniectomy and C1-C2 laminectomy respiratory problems did not recur during a 7 month post-operative period. We suggest that the respiratory problems in homozygous achondroplasia may be due to brainstem compression from an abnormally small foramen magnum.

Achondroplasia↗
PubMed1985

Computerized tomography of the foramen magnum: achondroplastic values compared to normal standards.

Computerized tomographic dimensions of the foramen magnum of 63 achondroplastic individuals were compared to standards established for nonachondroplastic individuals. The size of the foramen magnum in patients with achondroplasia was small at all ages, particularly in those with serious neurologic problems. The data suggest that measurement of the foramen magnum may identify achondroplastic individuals at high risk of developing neurologic complications.

Achondroplasia↗
PubMed1984

Long-term neurological sequelae in achondroplasia.

Two children with achondroplasia and neurologic sequelae secondary to foramen magnum compression were found to have syringomyelia. In one patient, the cyst was associated with a subependymal glioma. These findings suggest that foramen magnum stenosis may lead to irreversible spinal cord damage.

Achondroplasia↗
PubMed1984

Genetic study of an orthopedic referral center.

A prospective study of patients seen at the Shriners Hospital for Crippled Children, Houston Unit, showed that there is a substantial genetic component to orthopedic disorders. A mean of 25% of new patients and 46% of specialty clinic patients had orthopedic diseases of genetic etiology. The respective single gene component was 7.2% and 12.9%. Rare disorders were observed, and some of these are discussed. The results indicate that genetic counseling should be an integral part of orthopedic care.

Adolescent↗
PubMed1984

Short-latency somatosensory evoked potentials in the management of patients with achondroplasia.

Twenty-three patients with achondroplasia were evaluated using short-latency somatosensory evoked potentials (SEPs) of median and peroneal nerves. Abnormal studies were found in 61%. All patients with neurologic signs or symptoms had abnormal SEPs, with good correlation between SEP results and the level of the lesion determined clinically and radiographically. SEPs were abnormal in 44% of neurologically intact achondroplasts, several of whom had CTs confirming significant foramen magnum stenosis. SEPs are an important noninvasive means of evaluating patients with achondroplasia and are particularly valuable in children to document neurologic compromise before significant and perhaps irreversible clinical impairment develops.

Achondroplasia↗