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L B Holmes

Publications and source records attributed to L B Holmes.

At least 55 records · Page 3Linked to original sources
PubMed1997

Mutations in human TBX3 alter limb, apocrine and genital development in ulnar-mammary syndrome.

Ulnar-mammary syndrome is a rare pleiotropic disorder affecting limb, apocrine gland, tooth and genital development. We demonstrate that mutations in human TBX3, a member of the T-box gene family, cause ulnar-mammary syndrome in two families. Each mutation (a single nucleotide deletion and a splice-site mutation) is predicted to cause haploinsufficiency of TBX3, implying that critical levels of this transcription factor are required for morphogenesis of several organs. Limb abnormalities of ulnar-mammary syndrome involve posterior elements. Mutations in TBX5, a related and linked gene, cause anterior limb abnormalities in Holt-Oram syndrome. We suggest that during the evolution of TBX3 and TBX5 from a common ancestral gene, each has acquired specific yet complementary roles in patterning the mammalian upper limb.

Abnormalities, Multiple↗
PubMed1997

Severe malformation of one foot from amniocentesis needle injury.

An 11-year-old boy is described who was born with a poorly developed right foot. At 16 weeks gestation his mother had had amniocentesis without direct ultrasound guidance. After the insertion of the amniocentesis needle, she felt strong abdominal resistance, which disappeared with slight withdrawal of the needle. Then, real-time ultrasound was used to determine the position of the needle, which was reported to be up against the feet. Nine days later deep purple amniotic fluid was removed by amniocentesis. At birth there was a scab over an oozing hole in the lateral aspect of his right 'foot', a poorly formed structure with five digit-like structures at the tip. It seems most likely that the deformity was caused by tissue injury from needle puncture at 16 weeks gestation.

Adult↗
PubMed1996

Type III tracheal agenesis with familial tetralogy of Fallot and absent pulmonary valve syndrome.

We describe a female infant born at 33 weeks gestation diagnosed postnatally with a previously unreported phenotype consisting of Type III tracheal agenesis plus tetralogy of Fallot with absent pulmonary valve. She was delivered to a mother who had the same congenital heart malformation, but no detectable tracheal abnormality. We discuss possible etiologies of these malformations.

Abnormalities, Multiple↗
PubMed1996

Epidemiology of osteochondrodysplasias: changing trends due to advances in prenatal diagnosis.

The osteochondrodysplasias (skeletal dysplasias) are a heterogeneous group of disorders characterized by abnormalities in cartilage and bone growth and development. Some of these disorders are detectable during the second trimester by sonographic techniques. We ascertained cases of osteochondrodysplasias in elective pregnancy terminations, stillborn infants older than 20 gestational weeks, and liveborn infants diagnosed by the fifth day of life as part of an ongoing active malformation surveillance program. Forty-nine cases of osteochondrodysplasias were identified among approximately 126,000 deliveries at Brigham and Women's Hospital (BWH) during a 15-year period (Feb. 16, 1972-Feb. 15, 1975; Jan. 1, 1979-Dec. 31, 1990). When cases delivered to women who had planned to deliver at another hospital but were transferred for high-risk care (transfers) were excluded, the prevalence rate was 2.14 cases per 10,000 deliveries. During the early period (1972-1975) no cases were suspected prenatally, while during the 1988-1990 period, 80% of all cases and 57% of cases delivered to women who had always planned to deliver at BWH (non-transfers) were suspected by ultrasonography. Birth status changed through our period of surveillance. In the final 3-year period (1988-1990), 40% of all cases and 29% of non-transfers with osteochondrodysplasias were pregnancy terminations, compared to none during the 1972-1975 period. The increasing frequency of pregnancy terminations complicated the diagnosis of these conditions. Despite extensive evaluation, a definitive diagnosis was not possible in 8 of 49 cases (16%). Biochemical and molecular genetic methods of diagnosis will continue to become more important if the current trend of wide utilization of prenatal sonography and termination of affected pregnancies continues.

Abortion, Induced↗
PubMed1996

A study of level of lesion, associated malformations and sib occurrence risks in spina bifida.

Neural tube defects remain the most serious common birth defect and, despite considerable progress in understanding these malformations, the etiology of most cases remains unknown. It has been proposed that the cause may vary with the type and location of the malformation but, if these variables are to be studied, a rigorous classification of cases is required. This has become more important as birth prevalence has fallen, mainly due to prenatal diagnosis and elective termination of pregnancy, and future studies will increasingly require collaboration between centres. In this study we have combined data from Ottawa, Ontario, and Boston, Massachusetts, in an attempt to examine the effect of level of spina bifida on sib occurrence rates and the rates of associated malformations, and to compare the level of lesion when determined radiographically with that recorded on the clinical chart. Malformations appeared to be more frequent with thoracic spina bifida and were more often associated with additional vertebral anomalies. Significant differences were found between the upper level of lesion recorded in the clinical file and that visible radiographically. Sib recurrences were too few for statistical comparison, but the data suggest a higher rate among sibs and more distant relatives of propositi with upper level lesions. There was not evidence to support a greater than expected concordance for level of lesion between sibs.

Boston↗
PubMed1996

Increased detection of cystic hygroma: a "technology-induced phenomenon".

In this study, we have determined the increasing rate of detection of cystic hygroma in an urban hospital-based Active Malformations Surveillance Program during 1973-1974, 1979-1980, 1984-1985, and 1989-1990. All affected infants were identified from a review of the findings in either the findings in the pediatricians' examinations, the autopsy reports or the reports of finding in prenatal ultrasonography. The infants were subdivided by maternal transfer status and age (> or = 5 or < 35), the presence of associated chromosome abnormalities and malformations and birth status. Eighty-four affected infants and fetuses were identified, 47 of whose mothers were nontransfers. Among the maternal nontransfers, the prevalence rate of cystic hygroma increased from 0.08/1,000 in 1973-1974 to 1.45/1,000 in 1988-1990. Initially, the diagnosis was made at birth in liveborn or stillborn infants, but by 1989-1990, only by prenatal ultrasonography. Most (71%) of the pregnancies with affected fetuses were terminated by choice following diagnosis with prenatal ultrasonography. A marked increase in the frequency of examination by sonography during pregnancy was observed among a comparison group of women between 1974 and 1989. The progressive increase in the detection of cystic hygroma in this time period was one effect of this more extensive use of prenatal ultrasound, better equipment, and more experienced sonographers.

Boston↗
PubMed1996

Prospective study showing that antisperm antibodies are not associated with pregnancy losses.

OBJECTIVE: To obtain prospective data on the relationship between presence of antisperm antibodies in maternal sera and first trimester pregnancy losses. DESIGN: First trimester sera obtained from diabetic and nondiabetic women recruited within 21 days of conception were analyzed using the indirect immunobead test for immunoglobulin (Ig)G, IgA, and IgM antisperm antibodies. Regional binding also was considered: sperm head, midpiece, and sperm tail. Results were correlated with pregnancy outcome. SETTING: Five university centers. PATIENTS: One hundred eleven women who experienced pregnancy loss (55 diabetic; 56 nondiabetic) were matched 2:1 with 104 diabetic and 116 nondiabetic women (controls) who subsequently had a normal liveborn infant. INTERVENTION: None. MAIN OUTCOME MEASURE: Pregnancy outcome (spontaneous abortion, liveborn) correlated with presence or absence of antisperm antibodies. RESULTS: Analyzing samples without knowledge of clinical status, no differences were observed with respect to IgG, IgA, and IgM binding when a positive test was defined as 50% of sperm showing antibody binding. Likewise, no association was found for IgG and IgM antisperm antibodies at 20% binding. The only positive finding was observed for IgA antisperm antibodies at 20% binding (Fisher's Exact test). This one positive finding merely could reflect multiple comparisons. No significant differences between groups were observed when analysis was stratified according to location of antibody binding (head, midpiece, tail tip, entire sperm). When the sample was stratified into those having and not having a prior loss, a relationship between antisperm antibodies and pregnancy loss still was not evident. CONCLUSION: Further work is necessary to determine whether IgA antisperm antibodies truly are associated with pregnancy loss or whether antisperm antibodies play any role in repetitive aborters. Findings in this study suggest that antisperm antibodies do not play a major role in pregnancy loss.

Abortion, Spontaneous↗
PubMed1996

Infectious processes: an infrequent cause of first trimester spontaneous abortions.

A systematic assessment of infections beginning early in pregnancy is necessary to determine the true role of infections in pregnancy loss, given that infections could readily arise only after fetal demise. To this end, we have prospectively determined the frequency of infections in pregnant women who were subjects in a multi-centre US study. Insulin-dependent diabetic subjects and controlled subjects were recruited either before conception (86%) or at the latest within 21 days of conception (14%). We collected data prospectively on all important risk factors and potential confounding variables, seeing 386 diabetic subjects weekly and 432 control subjects every other week during the first trimester. At each visit we inquired about untoward events and explicitly about fever or infections. We found no clinical evidence that infection occurred more often in the 116 subjects experiencing pregnancy loss as compared to the 702 having successful pregnancies. This held both for the 2 week interval in which a given loss was recognized clinically as well as in the prior 2 week interval. Similar findings were not only observed for both the control as well as diabetic subjects but also when data were stratified by genital infection only or by systemic infection only. Our prospective data suggest that the attributable risk of infection in first trimester spontaneous abortion is small.

Abortion, Spontaneous↗
PubMed1996

The genetic and clinical heterogeneity of gonadotropin-releasing hormone deficiency in the human.

Despite recent advances in the understanding of the pathophysiology of Kallmann's syndrome (KS), the patterns of inheritance in the majority of cases of GnRH deficiency in human subjects remain unclear. To define further the genetic and phenotypic variability of this syndrome, detailed family histories were reviewed in 106 cases of GnRH deficiency with or without anosmia [i.e. KS or idiopathic hypogonadotropic hypogonadism (IHH)]. The great majority of cases appeared to be sporadic, with only 19 probands (18%) having at least 1 family member with GnRH deficiency. However, of the families in which the proband was the sole member affected by KS or IHH, 9 had individuals with isolated anosmia, and 8 had a strong history of delayed puberty. If these phenotypes were considered as alternative manifestations of the same genetic defect that presented as KS or IHH in the proband, 34% of the cases in the present series could be considered familial. In these families, the most likely modes of transmission were assessed in several ways, including analysis of probands with KS as a distinct subset, and separate determinations based upon whether the phenotypes of isolated anosmia and/or delayed puberty were considered relevant to the inheritance of KS or IHH. The proportion of familial cases that could be attributable to an X-linked mode of inheritance was no greater than 36% in any of these analyses. We conclude that 1) most cases of GnRH deficiency in humans are sporadic and, thus, could represent new mutations; 2) the X-linked form is the least common among familial cases of KS or IHH; 3) defects in at least two autosomal genes can results in GnRH deficiency; and 4) associated clinical defects may well represent clues to the nature and/or location of these autosomal genes.

Female↗
PubMed1996

Reproductive and developmental effects of disinfection by-products in drinking water.

Recent epidemiologic studies have reported associations between the consumption of chlorinated drinking water and reproductive and developmental effects. Here we review the available epidemiologic data, assess the hazard potential posed by exposure to disinfection by-products, identify critical data gaps, and offer recommendations for further research. The epidemiologic evidence supporting associations between exposure to water disinfection by-products (DBPs) and adverse pregnancy outcomes is sparse, and positive findings should be interpreted cautiously. The methods used during the early stages of research in this area have been diverse. Variability in exposure assessment and endpoints makes it difficult to synthesize or combine the available data. Exposure misclassification and unmeasured confounding may have lead to bias in risk estimation. Future studies of reproductive outcome and exposure to chlorinated water should use improved methods for exposure assessment to 1) assure selection of appropriate exposure markers, 2) assess seasonal and annual fluctuations in DBPs, 3) assess variability within the distribution system, and 4) assess exposure through multiple routes such as bathing and showering, as well as consumption. Population-based studies should be conducted to evaluate male and female fertility, conception delay, growth retardation, and specific birth defects. The reproductive and developmental effects of exposure to DBPs could be efficiently explored in ongoing investigations by incorporating valid exposure markers and relevant questionnaire information. Future studies should make use of naturally occurring variability in the concentrations of DBPs and may incorporate biomarkers of exposure and effect in their design. Epidemiologic investigations should be conducted in parallel with laboratory-based and animal studies in a coordinated, multidisciplinary approach.

Abnormalities, Drug-Induced↗
PubMed1995

Genetic heterogeneity of heart-hand syndromes.

BACKGROUND: Heart-hand syndromes compose a class of combined congenital cardiac and limb deformities. The proto-typical heart-hand disorder is Holt-Oram syndrome, which is characterized by cardiac septation defects and radial ray limb deformity. We have recently mapped the Holt-Oram syndrome gene defect to the long arm of human chromosome 12 in two families. The role of this disease locus in the pathogenesis of related conditions such as heart-hand syndrome type III (cardiac conduction disease accompanied by skeletal malformations) or familial atrial septal defects is unknown. METHODS AND RESULTS: Clinical evaluations and genetic linkage analyses were performed in five additional kindreds with Holt-Oram syndrome and also in one kindred with heart-hand syndrome type III and one kindred with familial atrial septal defect and conduction disease. Holt-Oram syndrome in all five kindreds mapped to chromosome 12q2. These studies and previous data provide odds of greater than 10(25):1 that the Holt-Oram syndrome disease gene is at chromosome 12q2. In contrast, neither the phenotypically similar disorder heart-hand syndrome type III nor the locus responsible for a familial atrial septal defect with atrioventricular block maps to chromosome 12q2. CONCLUSIONS: We demonstrate that heart-hand syndromes are genetically heterogeneous. Conditions that clinically appear to be partial phenocopies of Holt-Oram syndrome arise from distinct disease genes.

Chromosomes, Human, Pair 12↗
PubMed1995

Genital abnormalities in females with Bardet-Biedl syndrome.

The major manifestations of the Bardet-Biedl syndrome are digital anomalies, tapetoretinal degeneration, obesity, renal abnormalities, and hypogenitalism (described mainly in males). We report on 2 girls with Bardet-Biedl syndrome who also had vaginal atresia. A similar association in females with Bardet-Biedl syndrome was suggested in published reports of 11 affected individuals who had structural genital abnormalities, (some of which were missed in childhood), including persistent urogenital sinus, ectopic urethra, hypoplasia of the uterus, ovaries and fallopian tubes, uterus duplex, and septate vagina. The association of atresia of the vagina and other malformations of female genital structures in individuals with Bardet-Biedl syndrome has often been missed in childhood and should be looked for more systematically.

Child↗