Mutations in the human delta homologue, DLL3, cause axial skeletal defects in spondylocostal dysostosis.

Spondylocostal dysostosis (SD, MIM 277300) is a group of vertebral malsegmentation syndromes with reduced stature resulting from axial skeletal defects. SD is characterized by multiple hemivertebrae, rib fusions and deletions with a non-progressive kyphoscoliosis. Cases may be sporadic or familial, with both autosomal dominant and autosomal recessive modes of inheritance reported. Autosomal recessive SD maps to a 7.8-cM interval on chromosome 19q13.1-q13.3 that is homologous with a mouse region containing a gene encoding the Notch ligand delta-like 3 (Dll3). Dll3 is mutated in the X-ray-induced mouse mutant pudgy (pu), causing a variety of vertebrocostal defects similar to SD phenotypes. Here we have cloned and sequenced human DLL3 to evaluate it as a candidate gene for SD and identified mutations in three autosomal recessive SD families. Two of the mutations predict truncations within conserved extracellular domains. The third is a missense mutation in a highly conserved glycine residue of the fifth epidermal growth factor (EGF) repeat, which has revealed an important functional role for this domain. These represent the first mutations in a human Delta homologue, thus highlighting the critical role of the Notch signalling pathway and its components in patterning the mammalian axial

HRPT2, encoding parafibromin, is mutated in hyperparathyroidism-jaw tumor syndrome.

We report here the identification of a gene associated with the hyperparathyroidism-jaw tumor (HPT-JT) syndrome. A single locus associated with HPT-JT (HRPT2) was previously mapped to chromosomal region 1q25-q32. We refined this region to a critical interval of 12 cM by genotyping in 26 affected kindreds. Using a positional candidate approach, we identified thirteen different heterozygous, germline, inactivating mutations in a single gene in fourteen families with HPT-JT. The proposed role of HRPT2 as a tumor suppressor was supported by mutation screening in 48 parathyroid adenomas with cystic features, which identified three somatic inactivating mutations, all located in exon 1. None of these mutations were detected in normal controls, and all were predicted to cause deficient or impaired protein function. HRPT2 is a ubiquitously expressed, evolutionarily conserved gene encoding a predicted protein of 531 amino acids, for which we propose the name parafibromin. Our findings suggest that HRPT2 is a tumor-suppressor gene, the inactivation of which is directly involved in predisposition to HPT-JT and in development of some sporadic parathyroid tumors.

Hereditary sacrococcygeal teratoma--not the same as its sporadic counterpart!

Sacrococcygeal teratoma (SCT) can be sporadic or familial and there appear to be different characteristics to these entities. It can be an isolated anomaly or occur as part of the Currarino triad, when it is associated with anorectal malformations and sacral anomalies. We present a case of familial sacrococcygeal teratoma and discuss its relationship to previously published reports, drawing conclusions regarding embryogenesis, diagnosis, screening and management.

Novel mutations in DLL3, a somitogenesis gene encoding a ligand for the Notch signalling pathway, cause a consistent pattern of abnormal vertebral segmentation in spondylocostal dysostosis.

The spondylocostal dysostoses (SCD) are a group of disorders characterised by multiple vertebral segmentation defects and rib anomalies. SCD can either be sporadic or familial, and can be inherited in either autosomal dominant or recessive modes. We have previously shown that recessive forms of SCD can be caused by mutations in the delta-like 3 gene, DLL3. Here, we have sequenced DLL3 in a series of SCD cases and identified 12 mutations in a further 10 families. These include 10 novel mutations in exons 4-8, comprising nonsense, missense, frameshift, splicing, and in frame insertion mutations that are predicted to result in either the truncation of the mature protein in the extracellular domain, or affect highly conserved amino acid residues in the epidermal growth factor-like repeats of the protein. The affected cases represent diverse ethnic backgrounds and six come from traditionally consanguineous communities. In all affected subjects, the radiological phenotype is abnormal segmentation throughout the entire vertebral column with smooth outlines to the vertebral bodies in childhood, for which we suggest the term "pebble beach sign". This is a very consistent phenotype-genotype correlation and we suggest the designation SCD type 1 for the AR form caused by mutations in the DLL3 gene.

Long term health and neurodevelopment in children exposed to antiepileptic drugs before birth.

OBJECTIVE: To investigate the frequency of neonatal and later childhood morbidity in children exposed to antiepileptic drugs in utero. DESIGN: Retrospective population based study. SETTING: Population of the Grampian region of Scotland. PARTICIPANTS: Mothers taking antiepileptic drugs in pregnancy between 1976 and 2000 were ascertained from hospital obstetric records and 149 (58% of those eligible) took part. They had 293 children whose health and neurodevelopment were assessed. MAIN OUTCOME MEASURES: Frequencies of neonatal withdrawal, congenital malformations, childhood onset medical problems, developmental delay, and behaviour disorders. RESULTS: Neonatal withdrawal was seen in 20% of those exposed to antiepileptic drugs. Congenital malformations occurred in 14% of exposed pregnancies, compared with 5% of non-exposed sibs, and developmental delay in 24% of exposed children, compared with 11% of non-exposed sibs. After excluding cases with a family history of developmental delay, 19% of exposed children and 3% of non-exposed sibs had developmental delay, 31% of exposed children had either major malformations or developmental delay, 52% of exposed children had facial dysmorphism compared with 25% of those not exposed, 31% of exposed children had childhood medical problems (13% of non-exposed sibs), and 20% had behaviour disorders (5% of non-exposed). CONCLUSION: Prenatal antiepileptic drug exposure in the setting of maternal epilepsy is associated with developmental delay and later childhood morbidity in addition to congenital malformation.

Dwarfism, rhizomelic limb shortness, and abnormal face: new short stature syndrome sharing some manifestations with Robinow syndrome.

We describe a child with short stature of prenatal onset, rhizomelic limb shortness affecting the upper limbs particularly, and an unusual face. She had frontal balding, mid-face hypoplasia, a small nose, macrostomia with down-turned corners of the mouth, gingival hypertrophy, and hypoplasia or absence of the clitoris. There was no gross modelling defect of the skeleton and the vertebral column was normal. Some of these manifestations overlap with those of Robinow syndrome.

Developing diagnostic criteria for the fetal anticonvulsant syndromes.

The prevalence of congenital malformations and cognitive disorders in children whose mothers took antiepileptic drugs in pregnancy is increased, compared with the background rate. Not all such cases are due to teratogenic effects of the mother's treatment. Certain problems, including neonatal withdrawal symptoms, some malformations, characteristics facial features and a typical developmental and behavioural pattern may be indicators of a probable teratogenic event. We describe a set of diagnostic criteria which may assist in defining which children are likely to have a fetal anticonvulsant syndrome. This may help future research to identify risk factors which predispose to an adverse fetal outcome.

Severe prenatal infantile cortical hyperostosis (Caffey's disease).

We describe three cases of prenatal infantile cortical hyperostosis (Caffey's disease) from two families, all associated with maternal polyhydramnios. Case 1 (family 1) was an early early neonatal death after delivery at 27 weeks gestation, case 2 (family 2) an intrauterine death at 33 weeks. Case 3 (family 2) had limited skeletal involvement and followed a course typical for Caffey's disease. Only six cases of prenatal Caffey's disease with extensive skeletal involvement have previously been described. Polyhydramnios was reported in all but one and the condition was lethal unless pregnancy reached term. To our knowledge cases 2 and 3 reported here represent the first description of Caffey's disease in which the prenatal lethal form was not sporadic.

A four generation hidrotic ectodermal dysplasia family: an allelic variant of Clouston syndrome?

A four generation Scottish family with hidrotic ectodermal dysplasia affecting predominantly teeth, skin and hair is described. Hypo- or oligodontia of the secondary dentition by late adolescence was characteristic and two individuals had multiple natal teeth. Flexural acanthosis nigricans during childhood and early adolescence is a feature in some of the women. All affected individuals produced sweat, but heat tolerance was variable. Hypoplasia of the pilosebaceous units was found on light microscopy in one subject. Scalp hair was thin and slow growing (but adult females described much improved quality during pregnancy) and body hair was scanty. Scanning electron microscopy of hair samples showed abnormal cuticular appearances consistent with a primary defect affecting keratin structure. The nails were normal. Relative macrocephaly due to hyperostosis of the cranial vault was variably present. Short stature (5-10th centile) present in some cases is possibly a separate familial trait. The family demonstrates overlapping features with Clouston syndrome. In Clouston syndrome, however, alopecia can be severe, palmarplantar hyperkeratosis is usually present, and hypo/oligodontia is not a prominent feature.

Ectrodactyly-mandibulo-facial dysostosis: case report and delineation of an entity.

We describe a 24-year-old woman with tetramelic ectrodactyly, mandibulo-facial dysostosis and cleft uvula. This rare association has previously been reported in two families, but with ectrodactyly affecting only the feet. We propose the new term ectrodactyly-mandibulo-facial dysostosis for this entity.

Mutation of the LUNATIC FRINGE gene in humans causes spondylocostal dysostosis with a severe vertebral phenotype.

The spondylocostal dysostoses (SCDs) are a heterogeneous group of vertebral malsegmentation disorders that arise during embryonic development by a disruption of somitogenesis. Previously, we had identified two genes that cause a subset of autosomal recessive forms of this disease: DLL3 (SCD1) and MESP2 (SCD2). These genes are important components of the Notch signaling pathway, which has multiple roles in development and disease. Here, we have used a candidate-gene approach to identify a mutation in a third Notch pathway gene, LUNATIC FRINGE (LFNG), in a family with autosomal recessive SCD. LFNG encodes a glycosyltransferase that modifies the Notch family of cell-surface receptors, a key step in the regulation of this signaling pathway. A missense mutation was identified in a highly conserved phenylalanine close to the active site of the enzyme. Functional analysis revealed that the mutant LFNG was not localized to the correct compartment of the cell, was unable to modulate Notch signaling in a cell-based assay, and was enzymatically inactive. This represents the first known mutation in the human LFNG gene and reinforces the hypothesis that proper regulation of the Notch signaling pathway is an absolute requirement for the correct patterning of the axial skeleton.

Characteristics of fetal anticonvulsant syndrome associated autistic disorder.

The aim of this study was to evaluate the clinical features and frequency of autistic disorder or Asperger syndrome (AS; according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition [DSM-IV] criteria) in children exposed to anticonvulsant medication in utero. During a 20-year study period, 626 children were born in Aberdeen to mothers taking antiepileptic drugs (AEDs). The study examined long-term effects of prenatal exposure to AEDs in 260 children (122 males, 138 females). Of these, 26 (16 males) were reported by parents to have social or behavioural difficulties. Eleven children (6 males, 5 females) fulfilled the DSM-IV criteria for autistic disorder and one (female) fulfilled the DSM-IV criteria for AS. These children comprised 4.6% of the exposed children studied, and 1.9% of all exposed children born during the study period. Mean age of these children at diagnosis was 5 years 4 months (SD 2y 11mo) and 9 years 10 months (SD 3y 10mo) at the time of this study. Other children from the group of 26 had difficulties in areas of speech and language development and social communication but did not meet the criteria for an autism spectrum disorder (ASD). Sodium valproate was the drug most commonly associated with autistic disorder, five of 56 (8.9%) of the study children exposed to sodium valproate alone had either autistic disorder or AS. It was concluded that prenatal exposure to anticonvulsant medication is a risk factor for the development of an ASD. Fetal anticonvulsant syndrome associated autistic disorder is characterized by an even sex ratio, absence of regression or skill loss, and language delay in the absence of global delay.

Fractured clavicle of the newborn in a population with a high prevalence of grand-multiparity: analysis of 78 consecutive cases.

OBJECTIVE: To perform a clinical analysis of newborn babies with a fractured clavicle and investigate the possible role of relative calcium deficiency in the aetiology. DESIGN: Prospective descriptive study (clinical aspects); case controlled study (calcium, phosphate, alkaline phosphatase). SETTING: The Nazareth Hospital, Israel. SUBJECTS: All babies with a fractured clavicle detected in the newborn period and their mothers delivered between 23 August 1987 and 22 June 1989. The majority of the population were Arab. INTERVENTIONS: Serum calcium, phosphate and alkaline phosphatase were measured on the third postpartum day in 42 affected babies (with uncomplicated deliveries), their mothers, and a matched group of babies and mothers as controls. MAIN OUTCOME MEASURES: Clinical associations of fractured clavicle of the newborn; statistical comparison of affected group with controls (calcium study). RESULTS: The incidence of fractured clavicle was 18.7 per 1000 singleton vaginal births; 38 in the posterior clavicle at delivery, 27 in the anterior, position unascertained in nine. Four (5.2%) occurred in instrumental deliveries, three (3.9%) in assisted breech delivery; shoulder dystocia was noted in 13. The male to female ratio of 51:26 was significantly different but not due to birth weight. Affected babies were significantly heavier than the unaffected population. The incidence was higher in parous mothers older than 25 years of age but there was no evidence of increased incidence with increasing parity. No significant results were obtained in the calcium study between affected babies and their mothers, when compared with controls. CONCLUSIONS: Fractured clavicle of the newborn is a benign form of birth trauma from which heavier babies are at greater risk. It occurs in 1 to 2% of deliveries, most of these being uncomplicated vaginal births, and is often undetected. There is no evidence for relative calcium deficiency.

Evidence for variable gene expression in a large inbred kindred with autosomal recessive spondylocostal dysostosis.

Seven members of a large inbred kindred with autosomal recessive spondylocostal dysostosis were examined clinically, radiographically, and sonographically. The subjects were three adults, one adolescent, and three children under 3 years of age. One child was the offspring of a first cousin marriage which showed quasi-dominant inheritance. Six subjects had short stature owing to widespread vertebral dyssegmentation with variable reduction in rib number and rib fusion. One subject was of normal stature, had limited vertebral dyssegmentation, an extra rib, and no rib fusion. Five subjects showed the plagiocephaly-torticollis sequence. Four of the five male subjects had inguinal herniation on one or both sides. All subjects had normal renal ultrasonography. The youngest subject died of cardiopulmonary complications and is thought to represent one extreme in the expressivity of the gene in this kindred.