Cohort profile: the BABY1000 pilot prospective longitudinal birth cohort study based in Sydney, Australia

PURPOSE

The health of parents prior to conception, a woman's health during pregnancy and the infant's environment across their first months and years collectively have profound effects on the child's health across the lifespan. Since there are very few cohort studies in early pregnancy, gaps remain in our understanding of the mechanisms underpinning these relationships, and how health may be optimised. 'BABY1000', a pilot prospective longitudinal birth cohort study, aims to (1) identify factors before and during pregnancy and early life that impact longer-term health and (2) assess the feasibility and acceptability of study design to inform future research.

PARTICIPANTS

Participants were based in Sydney, Australia. Women were recruited at preconception or 12 weeks' gestation, and data were collected from them throughout pregnancy and postpartum, their children until the age of 2 years, and dietary information from a partner (if able) at the last study visit. The pilot aimed to recruit 250 women. However, recruitment ceased earlier than planned secondary to limitations from the COVID-19 pandemic and the final number of subjects was 225.

FINDINGS TO DATE

Biosamples, clinical measurements and sociodemographic/psychosocial measures were collected using validated tools and questionnaires. Data analysis and 24-month follow-up assessments for children are ongoing. Key early findings presented include participant demographics and dietary adequacy during pregnancy. The COVID-19 pandemic and associated public health and research restrictions affected recruitment of participants, follow-up assessments and data completeness.

FUTURE PLANS

The BABY1000 study will provide further insight into the developmental origins of health and disease and inform design and implementation of future cohort and intervention studies in the field. Since the BABY1000 pilot was conducted across the COVID-19 pandemic, it also provides unique insight into the early impacts of the pandemic on families, which may have effects on health across the lifespan.

Opioid treatment for opioid withdrawal in newborn infants

BACKGROUND

Neonatal abstinence syndrome (NAS) due to opioid withdrawal may result in disruption of the mother-infant relationship, sleep-wake abnormalities, feeding difficulties, weight loss, seizures and neurodevelopmental problems.

OBJECTIVES

To assess the effectiveness and safety of using an opioid for treatment of NAS due to withdrawal from opioids in newborn infants.

SEARCH METHODS

We ran an updated search on 17 September 2020 in CENTRAL via Cochrane Register of Studies Web and MEDLINE via Ovid. We also searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for eligible trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi- and cluster-RCTs which enrolled infants born to mothers with opioid dependence and who were experiencing NAS requiring treatment with an opioid.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial eligibility and risk of bias, and independently extracted data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 16 trials (1110 infants) with NAS secondary to maternal opioid use in pregnancy. Seven studies at low risk of bias were included in sensitivity analysis. Opioid versus no treatment / usual care: a single trial (80 infants) of morphine and supportive care versus supportive care alone reported no difference in treatment failure (risk ratio (RR) 1.29, 95% confidence interval (CI) 0.41 to 4.07; very low certainty evidence). No infant had a seizure. The trial did not report mortality, neurodevelopmental disability and adverse events. Morphine increased days hospitalisation (mean difference (MD) 15.00, 95% CI 8.86 to 21.14; very low certainty evidence) and treatment (MD 12.50, 95% CI 7.52 to 17.48; very low certainty evidence), but decreased days to regain birthweight (MD -2.80, 95% CI -5.33 to -0.27) and duration (minutes) of supportive care each day (MD -197.20, 95% CI -274.15 to -120.25). Morphine versus methadone: there was no difference in treatment failure (RR 1.59, 95% CI 0.95 to 2.67; 2 studies, 147 infants; low certainty evidence). Seizures, neonatal or infant mortality and neurodevelopmental disability were not reported. A single study reported no difference in days hospitalisation (MD 1.40, 95% CI -3.08 to 5.88; 116 infants; low certainty evidence), whereas data from two studies found an increase in days treatment (MD 2.71, 95% CI 0.22 to 5.21; 147 infants; low certainty) for infants treated with morphine. A single study reported no difference in breastfeeding, adverse events, or out of home placement. Morphine versus sublingual buprenorphine: there was no difference in treatment failure (RR 0.79, 95% CI 0.36 to 1.74; 3 studies, 113 infants; very low certainty evidence). Neonatal or infant mortality and neurodevelopmental disability were not reported. There was moderate certainty evidence of an increase in days hospitalisation (MD 11.45, 95% CI 5.89 to 17.01; 3 studies, 113 infants), and days treatment (MD 12.79, 95% CI 7.57 to 18.00; 3 studies, 112 infants) for infants treated with morphine. A single adverse event (seizure) was reported in infants exposed to buprenorphine. Morphine versus diluted tincture of opium (DTO): a single study (33 infants) reported no difference in days hospitalisation, days treatment or weight gain (low certainty evidence). Opioid versus clonidine: a single study (31 infants) reported no infant with treatment failure in either group. This study did not report seizures, neonatal or infant mortality and neurodevelopmental disability. There was low certainty evidence for no difference in days hospitalisation or days treatment. This study did not report adverse events. Opioid versus diazepam: there was a reduction in treatment failure from use of an opioid (RR 0.43, 95% CI 0.23 to 0.80; 2 studies, 86 infants; low certainty evidence). Seizures, neonatal or infant mortality and neurodevelopmental disability were not reported. A single study of 34 infants comparing methadone versus diazepam reported no difference in days hospitalisation or days treatment (very low certainty evidence). Adverse events were not reported. Opioid versus phenobarbital: there was a reduction in treatment failure from use of an opioid (RR 0.51, 95% CI 0.35 to 0.74; 6 studies, 458 infants; moderate certainty evidence). Subgroup analysis found a reduction in treatment failure in trials titrating morphine to ≧ 0.5 mg/kg/day (RR 0.21, 95% CI 0.10 to 0.45; 3 studies, 230 infants), whereas a single study using morphine < 0.5 mg/kg/day reported no difference compared to use of phenobarbital (subgroup difference P = 0.05). Neonatal or infant mortality and neurodevelopmental disability were not reported. A single study (111 infants) of paregoric versus phenobarbital reported seven infants with seizures in the phenobarbital group, whereas no seizures were reported in two studies (170 infants) comparing morphine to phenobarbital. There was no difference in days hospitalisation or days treatment. A single study (96 infants) reported no adverse events in either group. Opioid versus chlorpromazine: there was a reduction in treatment failure from use of morphine versus chlorpromazine (RR 0.08, 95% CI 0.01 to 0.62; 1 study, 90 infants; moderate certainty evidence). No seizures were reported in either group. There was low certainty evidence for no difference in days treatment. This trial reported no adverse events in either group. None of the included studies reported time to control of NAS. Data for duration and severity of NAS were limited, and we were unable to use these data in quantitative synthesis.

AUTHORS' CONCLUSIONS

Compared to supportive care alone, the addition of an opioid may increase duration of hospitalisation and treatment, but may reduce days to regain birthweight and the duration of supportive care each day. Use of an opioid may reduce treatment failure compared to phenobarbital, diazepam or chlorpromazine. Use of an opioid may have little or no effect on duration of hospitalisation or treatment compared to use of phenobarbital, diazepam or chlorpromazine. The type of opioid used may have little or no effect on the treatment failure rate. Use of buprenorphine probably reduces duration of hospitalisation and treatment compared to morphine, but there are no data for time to control NAS with buprenorphine, and insufficient evidence to determine safety. There is insufficient evidence to determine the effectiveness and safety of clonidine.

Sedatives for opioid withdrawal in newborn infants

BACKGROUND

Neonatal abstinence syndrome (NAS) due to opioid withdrawal may result in disruption of the mother-infant relationship, sleep-wake abnormalities, feeding difficulties, weight loss, seizures and neurodevelopmental problems.

OBJECTIVES

To assess the effectiveness and safety of using a sedative versus control (placebo, usual treatment or non-pharmacological treatment) for NAS due to withdrawal from opioids and determine which type of sedative is most effective and safe for NAS due to withdrawal from opioids.

SEARCH METHODS

We ran an updated search on 17 September 2020 in CENTRAL via CRS Web and MEDLINE via Ovid. We searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included trials enrolling infants with NAS born to mothers with an opioid dependence with more than 80% follow-up and using randomised, quasi-randomised and cluster-randomised allocation to sedative or control.

DATA COLLECTION AND ANALYSIS

Three review authors assessed trial eligibility and risk of bias, and independently extracted data. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 10 trials (581 infants) with NAS secondary to maternal opioid use in pregnancy. There were multiple comparisons of different sedatives and regimens. There were limited data available for use in sensitivity analysis of studies at low risk of bias. Phenobarbital versus supportive care: one study reported there may be little or no difference in treatment failure with phenobarbital and supportive care versus supportive care alone (risk ratio (RR) 2.73, 95% confidence interval (CI) 0.94 to 7.94; 62 participants; very low-certainty evidence). No infant had a clinical seizure. The study did not report mortality, neurodevelopmental disability and adverse events. There may be an increase in days' hospitalisation and treatment from use of phenobarbital (hospitalisation: mean difference (MD) 20.80, 95% CI 13.64 to 27.96; treatment: MD 17.90, 95% CI 11.98 to 23.82; both 62 participants; very low-certainty evidence). Phenobarbital versus diazepam: there may be a reduction in treatment failure with phenobarbital versus diazepam (RR 0.39, 95% CI 0.24 to 0.62; 139 participants; 2 studies; low-certainty evidence). The studies did not report mortality, neurodevelopmental disability and adverse events. One study reported there may be little or no difference in days' hospitalisation and treatment (hospitalisation: MD 3.89, 95% CI -1.20 to 8.98; 32 participants; treatment: MD 4.30, 95% CI -0.73 to 9.33; 31 participants; both low-certainty evidence). Phenobarbital versus chlorpromazine: there may be a reduction in treatment failure with phenobarbital versus chlorpromazine (RR 0.55, 95% CI 0.33 to 0.92; 138 participants; 2 studies; very low-certainty evidence), and no infant had a seizure. The studies did not report mortality and neurodevelopmental disability. One study reported there may be little or no difference in days' hospitalisation (MD 7.00, 95% CI -3.51 to 17.51; 87 participants; low-certainty evidence) and 0/100 infants had an adverse event. Phenobarbital and opioid versus opioid alone: one study reported no infants with treatment failure and no clinical seizures in either group (low-certainty evidence). The study did not report mortality, neurodevelopmental disability and adverse events. One study reported there may be a reduction in days' hospitalisation for infants treated with phenobarbital and opioid (MD -43.50, 95% CI -59.18 to -27.82; 20 participants; low-certainty evidence). Clonidine and opioid versus opioid alone: one study reported there may be little or no difference in treatment failure with clonidine and dilute tincture of opium (DTO) versus DTO alone (RR 0.09, 95% CI 0.01 to 1.59; 80 participants; very low-certainty evidence). All five infants with treatment failure were in the DTO group. There may be little or no difference in seizures (RR 0.14, 95% CI 0.01 to 2.68; 80 participants; very low-certainty evidence). All three infants with seizures were in the DTO group. There may be little or no difference in mortality after discharge (RR 7.00, 95% CI 0.37 to 131.28; 80 participants; very low-certainty evidence). All three deaths were in the clonidine and DTO group. The study did not report neurodevelopmental disability. There may be little or no difference in days' treatment (MD -4.00, 95% CI -8.33 to 0.33; 80 participants; very low-certainty evidence). One adverse event occurred in the clonidine and DTO group. There may be little or no difference in rebound NAS after stopping treatment, although all seven cases were in the clonidine and DTO group. Clonidine and opioid versus phenobarbital and opioid: there may be little or no difference in treatment failure (RR 2.27, 95% CI 0.98 to 5.25; 2 studies, 93 participants; very low-certainty evidence). One study reported one infant in the clonidine and morphine group had a seizure, and there were no infant mortalities. The studies did not report neurodevelopmental disability. There may be an increase in days' hospitalisation and days' treatment with clonidine and opioid versus phenobarbital and opioid(hospitalisation: MD 7.13, 95% CI 6.38 to 7.88; treatment: MD 7.57, 95% CI 3.97 to 11.17; both 2 studies, 91 participants; low-certainty evidence). There may be little or no difference in adverse events (RR 1.55, 95% CI 0.44 to 5.40; 2 studies, 93 participants; very low-certainty evidence). However, there was oversedation only in the phenobarbital and morphine group; and hypotension, rebound hypertension and rebound NAS only in the clonidine and morphine group.

AUTHORS' CONCLUSIONS

There is very low-certainty evidence that phenobarbital increases duration of hospitalisation and treatment, but reduces days to regain birthweight and duration of supportive care each day compared to supportive care alone. There is low-certainty evidence that phenobarbital reduces treatment failure compared to diazepam and very low-certainty evidence that  phenobarbital reduces treatment failure compared to chlorpromazine. There is low-certainty evidence of an increase in days' hospitalisation and days' treatment with clonidine and opioid compared to phenobarbital and opioid. There are insufficient data to determine the safety and incidence of adverse events for infants treated with combinations of opioids and sedatives including phenobarbital and clonidine.

COL1A1 C-propeptide cleavage site mutation causes high bone mass, bone fragility and jaw lesions: a new cause of gnathodiaphyseal dysplasia?

Gnathodiaphyseal dysplasia (GDD) is a rare autosomal dominant condition characterized by bone fragility, irregular bone mineral density (BMD) and fibro-osseous lesions in the skull and jaw. Mutations in Anoctamin-5 (ANO5) have been identified in some cases. We aimed to identify the causative mutation in a family with features of GDD but no mutation in ANO5, using whole exome capture and massive parallel sequencing (WES). WES of two affected individuals (a mother and son) and the mother's unaffected parents identified a mutation in the C-propeptide cleavage site of COL1A1. Similar mutations have been reported in individuals with osteogenesis imperfecta (OI) and paradoxically increased BMD. C-propeptide cleavage site mutations in COL1A1 may not only cause 'high bone mass OI', but also the clinical features of GDD, specifically irregular sclerotic BMD and fibro-osseous lesions in the skull and jaw. GDD patients negative for ANO5 mutations should be assessed for mutations in type I collagen C-propeptide cleavage sites.

Next-generation sequencing: a frameshift in skeletal dysplasia gene discovery

In the last decade, huge breakthroughs in genetics-driven by new technology and different statistical approaches-have resulted in a plethora of new disease genes identified for both common and rare diseases. Massive parallel sequencing, commonly known as next-generation sequencing, is the latest advance in genetics, and has already facilitated the discovery of the molecular cause of many monogenic disorders. This article describes this new technology and reviews how this approach has been used successfully in patients with skeletal dysplasias. Moreover, this article illustrates how the study of rare diseases can inform understanding and therapeutic developments for common diseases such as osteoporosis.

A report of three patients with MMP2 associated hereditary osteolysis

Osteolysis syndromes are rare hereditary disorders characterized by destruction and resorption of affected bones. The current study adds three new patients from two unrelated consanguineous families with a severe form of inherited osteolysis. Clinical examination, radiological, biochemical, ultrastructural and molecular studies were conducted. Clinical and radiological studies suggested the diagnosis of Torg-Winchester syndrome. The three affected patients were homozygous for novel MMP2 gene mutations which confirmed the diagnosis. Our patients are the first to be reported from Egypt thus, supporting the pan ethnic nature of the disease.

Expanding CEP290 mutational spectrum in ciliopathies

Ciliopathies are an expanding group of rare conditions characterized by multiorgan involvement, that are caused by mutations in genes encoding for proteins of the primary cilium or its apparatus. Among these genes, CEP290 bears an intriguing allelic spectrum, being commonly mutated in Joubert syndrome and related disorders (JSRD), Meckel syndrome (MKS), Senior-Loken syndrome and isolated Leber congenital amaurosis (LCA). Although these conditions are recessively inherited, in a subset of patients only one CEP290 mutation could be detected. To assess whether genomic rearrangements involving the CEP290 gene could represent a possible mutational mechanism in these cases, exon dosage analysis on genomic DNA was performed in two groups of CEP290 heterozygous patients, including five JSRD/MKS cases and four LCA, respectively. In one JSRD patient, we identified a large heterozygous deletion encompassing CEP290 C-terminus that resulted in marked reduction of mRNA expression. No copy number alterations were identified in the remaining probands. The present work expands the CEP290 genotypic spectrum to include multiexon deletions. Although this mechanism does not appear to be frequent, screening for genomic rearrangements should be considered in patients in whom a single CEP290 mutated allele was identified.

[The efficacy of local anaesthetics administered prior to castration of male suckling piglets]

Objective of this study was to examine the efficacy of various local anaesthetics (Procaine Hydrochloride, Procaine Hydrochloride + Epinephrin, Lidocaine Hydrochloride) used in castration of four to six day old male piglets. Animals of the control groups (I-IV) were treated analogous to the castration groups (V-IX) but not castrated. In groups I and V 15 minutes prior to castration/fixation the piglets were fixed as for injection but not medicated. The injection volume was standardised to 0.5 ml per testes. Local anaesthetics were applicated intratesticularly in five groups and intrascrotarly in two groups. Blood samples were taken shortly before and one, four and 24 hours after castration/fixation. The serum cortisol level was analysed to determine pain induced neuroendocrine stress reaction. To proof the tissue tolerance creatinkinase-(CK) and aspartataminotransferase-(AST) concentration were analysed. One, seven and 14 days after castration the healing process were evaluated by a wound score. Groups I to IV did not show any increase of the serum cortisol level. Contrary one hour after castration the average cortisol concentration of castration groups (V-IX) rose significantly. Cortisol concentration of the medicated castration groups (VI-IX) showed a comparable or even higher cortisol level as the not medicated control group (V). Determination of CK and AST indicated no tissue damage of the application of the local anaesthetics. The administration of local anaesthetics prior to the castration did not have any effect on the wound healing process. The results of this study lead to the conclusion that injection of local anaesthetics show a good tissue tolerance but the call for reduction of the castration pain by presurgical injection of Procaine Hydrochloride or Lidocaine Hydrochloride is not justified.

Right-sided diaphragmatic eventration: a rare cause of non-immune hydrops fetalis

We report 2 cases of non-immune hydrops fetalis (NIHF) in which autopsy findings revealed an association with right-sided congenital diaphragmatic eventration (CDE). Both patients born at 30 weeks of gestation presented with severe generalized skin oedema, pleural effusions and ascites. They both died shortly after birth of cardiorespiratory insufficiency due to lung hypoplasia and low output heart failure. The right thoracic cavity was filled with the membranous but intact right diaphragm covering the herniated visceral organs including parts of the liver, small bowel and colon surrounded by voluminous ascites. In similar fashion to the situation seen in congenital diaphragmatic hernia (CDH), the displaced visceral organs led to impaired lung growth resulting in important lung hypoplasia and obstructed venous return. Extravascular liquid accumulation was probably further aggravated by hypoproteinaemia secondary to liver dysfunction resulting from the venous congestion and cardiac failure. In summary, CDE is a rare condition resulting from impaired ingrowth of muscle fibres into the diaphragm during the first trimester. Prenatal differentiation of CDE from CDH is a real challenge. The association of CDE and NIHF has not been previously described.

Lähmungserscheinungen bei Mastschweinen aufgrund einer bakteriellen Hirnstamm-Meningoenzephalitis, verursacht durch eine aufsteigende Zahnfach- und Kieferhöhlenentzündung

Gegenstand und Ziel: Diagnostische Abklärung von Lähmungserscheinungen, die vereinzelt bei Mastschweinen bis 60 kg in einem Bestand mit 900 Mastplätzen auftraten. Material und Methoden: Ein männlich-kastrierter Mastläufer aus dem Bestand wurde in die Klinik für Schweine der Ludwig-Maximilians-Universität München eingeliefert und klinisch, labordiagnostisch und pathologisch- anatomisch untersucht. Ergebnisse: Der schlecht genährte Läufer befand sich in rechter Seitenlage mit Kopfschiefhaltung nach rechts. Er hatte kein Stehvermögen und Gehversuche waren auch mit Unterstützung nicht möglich. Die neurologische Untersuchung ergab einen normalen Analreflex, normale After- und Zwischenklauenreflexe an allen vier Gliedmaßen sowie eine erhaltene Hautsensibilität. Der Kornealreflex des rechten Auges war erloschen. Die serologische Untersuchung lieferte keine Hinweise auf Aujeszky‘sche Krankheit (AK), Klassische Schweinepest (KSP) und Leptospira spp. Die Werte der hämatologischen und klinisch-chemischen Parameter lagen im Referenzbereich. Pathologisch-anatomisch wurde eine rechtsseitige Hirnstamm-Meningoenzephalitis mit Isolierung von Arcanobacterium pyogenes nachgewiesen. Der neuropathologische Befund ergab als Ursache für die Meningoenzephalitis eine Zahnfach- und Kieferhöhlenentzündung mit Ausbreitung über den Nervus maxillaris. Schlussfolgerung und klinische Relevanz: Als Ursache für Lähmungen der Gliedmaßen bei Läufern sollten auch aufsteigende Zahnfachentzündungen durch Zahnfrakturen oder falsch durchgeführte zootechnische Maßnahmen (Zähnezwicken) in Betracht gezogen werden.

Upregulation of ID protein by growth and differentiation factor 5 (GDF5) through a smad-dependent and MAPK-independent pathway in HUVSMC

GDF5 (growth and differentiation factor five), a member of the TGF-beta superfamily, binds specifically to BMPR1b, BMPR2 and ACTR2a receptors forming a heterodimeric complex, thereby inducing phosphorylation of smad1, 5, 8 and translocation to the nucleus. ID1 (inhibitor of differentiation or DNA binding) is essential for G1 to S phase transition inhibiting DNA binding thereby playing an important role in the control of differentiation, proliferation and angiogenesis. The objective of this study was, therefore, to characterize the signal transduction pathway of GDF5, especially the involvement of ID1, in human umbilical vein smooth muscle cells (HUVSMC). We observed the expression of BMPR1a, BMPR1b, BMPR2, ACTR2a, smad1, smad 5, ID1, ID2 and ID3 in HUVSMC. Application of GDF5 upregulated ID1 and ID3 expression by involvement of the smad signaling pathway. GDF5 caused phorsphorylation of smad1 followed by upregulation of ID1 and ID3. Co-incubation with anti-GDF5 prevented these effects. GDF5 significantly inhibited phosphorylation of p38 MAPK and induced phosphorylation of ERK. The specific inhibitor of p38 MAPK or ERK, SB203580 or U0126 did not induce ID protein expression. Smad1 siRNA transfection inhibited the upregulation of ID protein. GDF5 had chemotactic activity in HUVSMC; this effect was partly blocked by transfection of smad1 or ID1 siRNA. Our results indicate that GDF5 induces ID1 and ID3 in HUVSMC by a smad-dependent, MAPK-independent pathway. GDF5 binds to specific receptors, thereby inducing phosphorylation and translocation of smad1 to the nucleus where it is involved in the regulation of transcription. Since ID1 has been shown to be crucial for cell cycle control, we propose that GDF5 could be involved in the process of angiogenesis.

Expression of nitric oxide related enzymes in coronary heart disease

Enzymes involved in the metabolism nitric oxide (NO) and reactive oxygen species (ROS) may play a role for the decreased availability of NO in atherosclerosis. We, therefore, hypothesized that the pattern of gene expression of these enzymes is altered in atherosclerosis. Myocardial tissue from patients with coronary heart disease (CHD) or without CHD (control group) was investigated. The level of enzymes related to NO/ROS metabolism was determined both at mRNA level and protein level by rt-PCR, real-time PCR, and western blot. The expression of NOS1-3 (synthesis of NO), arginase1 (reduction of L-arginine), p22phox (active subunit of NADPH oxidase), GTPCH (rate limiting enzyme for tetrahydrobiopterin), SOD1-3 (scavengers of superoxide anions), PRTMT1-3, and DDAH2 (involved in the metabolism of ADMA) was determined. All enzymes were found to be expressed in human myocardium. NOS isoforms were decreased in CHD in protein level, but only the downregulation of NOS3 expression reached statistical significance. The expression of PRMT1 and PRMT3 was increased. In addition, the expression of DDAH2 was reduced, both theoretically leading to an increase of ADMA concentration. SOD3 was downregulated in tissue from patients with CHD. Taken together, in myocardial tissue from patients with atherosclerosis, the expression of genes increasing ADMA levels is enhanced in contrast to a reduced expression of genes promoting NO synthesis. These results may contribute to the explanation of increased oxidative stress in atherosclerosis on the level of gene expression.

The phenotypic spectrum in patients with arginine to cysteine mutations in the COL2A1 gene

BACKGROUND

The majority of COL2A1 missense mutations are substitutions of obligatory glycine residues in the triple helical domain. Only a few non-glycine missense mutations have been reported and among these, the arginine to cysteine substitutions predominate.

OBJECTIVE

To investigate in more detail the phenotype resulting from arginine to cysteine mutations in the COL2A1 gene.

METHODS

The clinical and radiographic phenotype of all patients in whom an arginine to cysteine mutation in the COL2A1 gene was identified in our laboratory, was studied and correlated with the abnormal genotype. The COL2A1 genotyping involved DHPLC analysis with subsequent sequencing of the abnormal fragments.

RESULTS

Six different mutations (R75C, R365C, R519C, R704C, R789C, R1076C) were found in 11 unrelated probands. Each mutation resulted in a rather constant and site-specific phenotype, but a perinatally lethal disorder was never observed. Spondyloarthropathy with normal stature and no ocular involvement were features of patients with the R75C, R519C, or R1076C mutation. Short third and/or fourth toes was a distinguishing feature of the R75C mutation and brachydactyly with enlarged finger joints a key feature of the R1076C substitution. Stickler dysplasia with brachydactyly was observed in patients with the R704C mutation. The R365C and R789C mutations resulted in classic Stickler dysplasia and spondyloepiphyseal dysplasia congenita (SEDC), respectively.

CONCLUSIONS

Arginine to cysteine mutations are rather infrequent COL2A1 mutations which cause a spectrum of phenotypes including classic SEDC and Stickler dysplasia, but also some unusual entities that have not yet been recognised and described as type II collagenopathies.

Winchester syndrome caused by a homozygous mutation affecting the active site of matrix metalloproteinase 2

The inherited osteolysis syndromes are a heterogeneous group of skeletal disorders whose classification is still uncertain. Three osteolysis syndromes show autosomal recessive inheritance and multicentric involvement: Torg syndrome (OMIM 259600), Winchester syndrome (OMIM 277950) and Nodulosis-Arthropathy-Osteolysis syndrome (NAO; OMIM 605156). The 2001 Nosology of the International Skeletal Dysplasia Society (Hall CM, Am J Med Genet 2002: 113: 65) classifies NAO as a variant of Torg syndrome, while Winchester syndrome is considered as a separate disorder. Recently, mutations in the matrix metalloproteinase 2 (MMP2) gene were identified in affected individuals with a clinical diagnosis of NAO in two Arab families. We report a homozygous missense mutation (E404K) in the active site of MMP2 in a 21-year-old woman with a severe form of osteolysis best compatible with a diagnosis of Winchester syndrome. The clinical and molecular findings suggest that Torg, NAO and Winchester syndromes are allelic disorders that form a clinical spectrum.

Fatal outcome in a female monozygotic twin with X-linked hypohydrotic ectodermal dysplasia (XLHED) due to a de novo t(X;9) translocation with probable disruption of the EDA gene

Ectodermal dysplasias are a group of congenital disorders with defective development of the epidermis and its appendages. X-linked hypohydrotic ectodermal dysplasia (XLHED; OMIM 305100) is the most common form of ectodermal dysplasia. We report on two monozygotic twin girls with XLHED due to a t(X;9) translocation causing a disruption of the EDA gene and non random inactivation of the normal X chromosome. One of the girls died unexpectedly at 2.5 years of age. Autopsy revealed that lack of normal tracheobronchial secretions leading to complete tracheal obstruction by mucous debris was the probable cause of death.

CONCLUSION

Morbidity and mortality of ectodermal dysplasias in infancy and early childhood can be significant. Early diagnosis by paediatricians is important and complications should be anticipated.

A characteristic EEG pattern in 4p-syndrome: case report and review of the literature

Deletions on the short arm of chromosome 4 cause Wolf-Hirschhorn syndrome (WHS) and Pitt-Rogers-Danks syndrome (PRDS). WHS is associated with severe growth and mental retardation, microcephaly, a characteristic facies and congenital malformations. The PRDS phenotype is similar to WHS but generally less severe. Seizures occur in the majority of WHS and PRDS patients. Sgrò et al. [17] described a stereotypic electroclinical pattern in four unrelated WHS patients, consisting of intermittent bursts of 2-3 Hz high voltage slow waves with spike wave activity in the parietal areas during drowsiness and sleep associated with myoclonic jerks. We report a patient with PRDS and the typical EEG pattern and review 14 WHS patients with similar EEG findings reported in the literature.

CONCLUSION

Awareness and recognition of the characteristic electroclinical findings in Wolf-Hirschhorn syndrome and Pitt-Rogers-Danks syndrome might help in the early diagnosis of such patients.

New chimaeric hepatitis B virus core particles carrying hantavirus (serotype Puumala) epitopes: immunogenicity and protection against virus challenge

Virus-like particles generated by the heterologous expression of virus structural proteins are able to potentiate the immunogenicity of foreign epitopes presented on their surface. In recent years epitopes of various origin have been inserted into the core antigen of hepatitis B virus (HBV) allowing the formation of chimaeric HBV core particles. Chimaeric core particles carrying the 45 N-terminal amino acids of the Puumala hantavirus nucleocapsid protein induced protective immunity in bank voles, the natural host of this hantavirus. Particles applied in the absence of adjuvant are still immunogenic and partially protective in bank voles. Although a C-terminally truncated core antigen of HBV (HBcAg delta) tolerates the insertion of extended foreign sequences, for the construction of multivalent vaccines the limited insertion capacity is still a critical factor. Recently, we have described a new system for generating HBV 'mosaic particles' in an Escherichia coli suppressor strain based on a readthrough mechanism on a stop linker located in front of the insert. Those mosaic particles are built up by both HBcAg delta and the HBcAg delta/Puumala nucleocapsid readthrough protein. The particles formed presented the 114 amino acid (aa) long hantavirus sequence, at least in part, on their surface and induced antibodies against the hantavirus sequence in bank voles. Variants of the stop linker still allowed the formation of mosaic particles demonstrating that stop codon suppression alone is sufficient for the packaging of longer foreign sequences in mosaic particles. Another approach to increase the insertion capacity is based on the simultaneous insertion of different Puumala nucleocapsid protein sequences (aa 1-45 and aa 75-119) into two different positions (aa 78 and behind aa 144) of a single HBcAg molecule. The data presented are of high relevance for the generation of multivalent vaccines requiring a high insertion capacity for foreign sequences.

Mosaic hepatitis B virus core particles allow insertion of extended foreign protein segments

Because of its particular immunological properties, the core protein of hepatitis B virus (HBcAg) has become one of the favoured 'virus-like particles' for use as a carrier of foreign epitopes. A new strategy to construct core particles presenting extended foreign protein segments was established based on the introduction of a linker containing a translational stop codon between sequences encoding a C-terminally truncated HBcAg (HBcAg delta) and a foreign protein sequence. Expression in an Escherichia coli suppressor strain allowed the simultaneous synthesis of both HBcAg delta and a read-through fusion protein containing a part of the hantavirus nucleocapsid protein. After purification, the presence of core-like mosaic particles with HBc and hantavirus antigenicity was demonstrated by electron microscopy and immunological tests. This strategy of partial stop codon suppression should improve the use of HBcAg as a carrier of foreign epitopes by allowing insertion of long foreign sequences into particle-forming proteins. The resulting mosaic particles should be of general interest for further vaccine developments.