Associations between attention-deficit hyperactivity disorder genetic liability and ICD-10 medical conditions in adults: utilizing electronic health records in a Phenome-Wide Association Study

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is often comorbid with other medical conditions in adult patients. However, ADHD is extremely underdiagnosed in adults and little is known about the medical comorbidities in undiagnosed adult individuals with high ADHD liability. In this study we investigated associations between ADHD genetic liability and electronic health record (EHR)-based ICD-10 diagnoses across all diagnostic categories, in individuals without ADHD diagnosis history.

METHODS

We used data from the Estonian Biobank cohort (N = 111 261) and generated polygenic risk scores (PRS) for ADHD (PRSADHD) based on the ADHD genome-wide association study. We performed a phenome-wide association study (PheWAS) to test for associations between standardized PRSADHD and 1515 EHR-based ICD-10 diagnoses in the full and sex-stratified sample. We compared the observed significant ICD-10 associations to associations with (1) ADHD diagnosis and (2) questionnaire-based high ADHD risk analyses.

RESULTS

After Bonferroni correction (p = 3.3 × 10-5) we identified 80 medical conditions associated with PRSADHD. The strongest evidence was seen with chronic obstructive pulmonary disease (OR 1.15, CI 1.11-1.18), obesity (OR 1.13, CI 1.11-1.15), and type 2 diabetes (OR 1.11, CI 1.09-1.14). Sex-stratified analysis generally showed similar associations in males and females. Out of all identified associations, 40% and 78% were also observed using ADHD diagnosis or questionnaire-based ADHD, respectively, as the predictor.

CONCLUSIONS

Overall our findings indicate that ADHD genetic liability is associated with an increased risk of a substantial number of medical conditions in undiagnosed individuals. These results highlight the need for timely detection and improved management of ADHD symptoms in adults.

The role of depression and antidepressant treatment in antihypertensive medication adherence and persistence: Utilising electronic health record data

Higher blood pressure levels in patients with depression may be associated with lower adherence to antihypertensive medications (AHMs). Here, we use electronic health record (EHR) data from the Estonian Biobank (EstBB) to investigate the role of lifetime depression in AHM adherence and persistence. We also explore the relationship between antidepressant initiation and intraindividual change in AHM adherence among hypertension (HTN) patients with newly diagnosed depression. Diagnosis and pharmacy refill data were obtained from the National Health Insurance database. Adherence and persistence to AHMs were determined for hypertension (HTN) patients initiating treatment between 2009 and 2017 with a three-year follow-up period. Multivariable regression was used to explore the associations between depression and AHM adherence or persistence, adjusting for sociodemographic, genetic, and health-related factors. A linear mixed-effects model was used to estimate the effect of antidepressant treatment initiation on antihypertensive medication adherence, adjusting for age and sex. We identified 20,724 individuals with newly diagnosed HTN (6294 depression cases and 14,430 controls). Depression was associated with 6% lower probability of AHM adherence (OR = 0.943, 95%CI = 0.909-0.979) and 12% lower odds of AHM persistence (OR = 0.876, 95%CI = 0.821-0.936). Adjusting for sociodemographic, genetic, and health-related factors did not significantly influence these associations. AHM adherence increased 8% six months after initiating antidepressant therapy (N = 132; β = 0.078; 95%CI = 0.025-0.131). Based on the EHR data on EstBB participants, depression is associated with lower AHM adherence and persistence. Additionally, antidepressant therapy may help improve AHM adherence in patients with depression.

Prenatal smoking, alcohol and caffeine exposure and offspring externalizing disorders: a systematic review and meta-analysis

BACKGROUND AND AIMS

Several studies have indicated an association between maternal prenatal substance use and offspring externalizing disorders; however, it is uncertain whether this relationship is causal. We conducted a systematic review to determine: (1) if the literature supports a causal role of maternal prenatal substance use on offspring externalizing disorders diagnosis and (2) whether these associations differ across externalizing disorders.

METHODS

We searched Web of Science, Embase, PsycINFO and Medline databases. Risk of bias assessment was conducted using the Newcastle-Ottawa Scale (NOS), and where possible meta-analysis was conducted for studies classed as low risk of bias. We included studies of any design that examined prenatal smoking, alcohol or caffeine use. Studies in non-English language, fetal alcohol syndrome and comorbid autism spectrum disorders were excluded. Participants in the included studies were mothers and their offspring. Measurements included prenatal smoking, alcohol or caffeine use as an exposure, and diagnosis of attention-deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional defiant disorder (ODD) in offspring as an outcome.

RESULTS

We included 63 studies, 46 of which investigated smoking and ADHD. All studies were narratively synthesized, and seven studies on smoking and ADHD were meta-analysed. The largest meta-analysis based on genetically sensitive design included 1 011 546 participants and did not find evidence for an association [odds ratio (OR)_{1-9 cigarettes}  = 0.90, 95% confidence interval (CI) = 0.83-1.11; OR _{> 10 cigarettes}  = 1.04, 95% CI = 0.79-1.36). Studies on alcohol exposure in all the outcomes reported inconsistent findings and no strong conclusions on causality can be made. Studies on caffeine exposure were mainly limited to ADHD and these studies do not support a causal effect.

CONCLUSIONS

There appears to be no clear evidence to support a causal relationship between maternal prenatal smoking and offspring attention-deficit hyperactivity disorder. Findings with alcohol and caffeine exposures and conduct disorder and oppositional-defiant disorder need more research, using more genetically sensitive designs.

Overview of CAPICE-Childhood and Adolescence Psychopathology: unravelling the complex etiology by a large Interdisciplinary Collaboration in Europe-an EU Marie Skłodowska-Curie International Training Network

The Roadmap for Mental Health and Wellbeing Research in Europe (ROAMER) identified child and adolescent mental illness as a priority area for research. CAPICE (Childhood and Adolescence Psychopathology: unravelling the complex etiology by a large Interdisciplinary Collaboration in Europe) is a European Union (EU) funded training network aimed at investigating the causes of individual differences in common childhood and adolescent psychopathology, especially depression, anxiety, and attention deficit hyperactivity disorder. CAPICE brings together eight birth and childhood cohorts as well as other cohorts from the EArly Genetics and Life course Epidemiology (EAGLE) consortium, including twin cohorts, with unique longitudinal data on environmental exposures and mental health problems, and genetic data on participants. Here we describe the objectives, summarize the methodological approaches and initial results, and present the dissemination strategy of the CAPICE network. Besides identifying genetic and epigenetic variants associated with these phenotypes, analyses have been performed to shed light on the role of genetic factors and the interplay with the environment in influencing the persistence of symptoms across the lifespan. Data harmonization and building an advanced data catalogue are also part of the work plan. Findings will be disseminated to non-academic parties, in close collaboration with the Global Alliance of Mental Illness Advocacy Networks-Europe (GAMIAN-Europe).

Prenatal smoking, alcohol and caffeine exposure and maternal-reported attention deficit hyperactivity disorder symptoms in childhood: triangulation of evidence using negative control and polygenic risk score analyses

BACKGROUND AND AIMS

Studies have indicated that maternal prenatal substance use may be associated with offspring attention deficit hyperactivity disorder (ADHD) via intrauterine effects. We measured associations between prenatal smoking, alcohol and caffeine consumption with childhood ADHD symptoms accounting for shared familial factors.

DESIGN

First, we used a negative control design comparing maternal and paternal substance use. Three models were used for negative control analyses: unadjusted (without confounders), adjusted (including confounders) and mutually adjusted (including confounders and partner's substance use). The results were meta-analysed across the cohorts. Secondly, we used polygenic risk scores (PRS) as proxies for exposures. Maternal PRS for smoking, alcohol and coffee consumption were regressed against ADHD symptoms. We triangulated the results across the two approaches to infer causality.

SETTING

We used data from three longitudinal pregnancy cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC) in the United Kingdom, Generation R study (GenR) in the Netherlands and Norwegian Mother, Father and Child Cohort study (MoBa) in Norway.

PARTICIPANTS

Phenotype data available for children were: N_ALSPAC  = 5455-7751; N_GENR  = 1537-3119; N_MOBA  = 28 053-42 206. Genotype data available for mothers was: N_ALSPAC  = 7074; N_MOBA  = 14 583.

MEASUREMENTS

A measure of offspring ADHD symptoms at age 7-8 years was derived by dichotomizing scores from questionnaires and parental self-reported prenatal substance use was measured at the second pregnancy trimester.

FINDINGS

The pooled estimate for maternal prenatal substance use showed an association with total ADHD symptoms [odds ratio (OR)_SMOKING  = 1.11, 95% confidence interval (CI) = 1.00-1.23; OR_ALCOHOL  = 1.27, 95% CI = 1.08-1.49; OR_CAFFEINE  = 1.05, 95% CI = 1.00-1.11], while not for fathers (OR_SMOKING  = 1.03, 95% CI = 0.95-1.13; OR_ALCOHOL  = 0.83, 95% CI = 0.47-1.48; OR_CAFFEINE  = 1.02, 95% CI = 0.97-1.07). However, maternal associations did not persist in sensitivity analyses (substance use before pregnancy, adjustment for maternal ADHD symptoms in MoBa). The PRS analyses were inconclusive for an association in ALSPAC or MoBa.

CONCLUSIONS

There appears to be no causal intrauterine effect of maternal prenatal substance use on offspring attention deficit hyperactivity disorder symptoms.

Maternal and child genetic liability for smoking and caffeine consumption and child mental health: an intergenerational genetic risk score analysis in the ALSPAC cohort

BACKGROUND AND AIMS

Previous studies suggest an association between maternal tobacco and caffeine consumption during and outside of pregnancy and offspring mental health. We aimed to separate effects of the maternal environment (intrauterine or postnatal) from pleiotropic genetic effects.

DESIGN

Secondary analysis of a longitudinal study. We (i) validated smoking and caffeine genetic risk scores (GRS) derived from published genome-wide association study (GWAS) for use during pregnancy, (ii) compared estimated effects of maternal and offspring GRS on childhood mental health outcomes and (iii) tested associations between maternal and offspring GRS on their respective outcomes.

SETTING

We used data from a longitudinal birth cohort study from England, the Avon Longitudinal Study of Parents and Children (ALSPAC).

PARTICIPANTS

Our sample included 7921 mothers and 7964 offspring.

MEASUREMENTS

Mental health and non-mental health phenotypes were derived from questionnaires and clinical assessments: 79 maternal phenotypes assessed during and outside of pregnancy and 71 offspring phenotypes assessed in childhood (<10 years) and adolescence (11-18 years).

FINDINGS

The maternal smoking and caffeine GRS were associated with maternal smoking and caffeine consumption during pregnancy (2nd trimester: Psmoking  = 3.0 × 10-7 , Pcaffeine  = 3.28 × 10-5 ). Both the maternal and offspring smoking GRS showed evidence of association with reduced childhood anxiety symptoms (βmaternal  = -0.033; βoffspring  = -0.031) and increased conduct disorder symptoms (βmaternal  = 0.024; βoffspring  = 0.030), after correcting for multiple testing. Finally, the maternal and offspring smoking GRS were associated with phenotypes related to sensation seeking behaviours in mothers and adolescence (e.g. increased symptoms of externalising disorders, extraversion and monotony avoidance). The caffeine GRS showed weaker evidence for associations with mental health outcomes.

CONCLUSIONS

We did not find strong evidence that maternal smoking and caffeine genetic risk scores have a causal effect on offspring mental health outcomes. Our results confirm that the smoking genetic risk scores also captures liability for sensation seeking personality traits.

Maternal and offspring genetic risk score analyses of fetal alcohol exposure and attention-deficit hyperactivity disorder risk in offspring

Background

Studies investigating the effects of prenatal alcohol exposure on childhood attention‐deficit hyperactivity disorder (ADHD) symptoms using conventional observational designs have reported inconsistent findings, which may be affected by unmeasured confounding and maternal and fetal ability to metabolize alcohol. We used genetic variants from the alcohol metabolizing genes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), as proxies for fetal alcohol exposure to investigate their association with risk of offspring ADHD symptoms around age 7–8 years.

Methods

We used data from 3 longitudinal pregnancy cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC), Generation R study (GenR), and the Norwegian Mother, Father and Child Cohort study (MoBa). Genetic risk scores (GRS) for alcohol use and metabolism using 36 single nucleotide polymorphisms (SNPs) from ADH and ALDH genes were calculated for mothers (N_ALSPAC = 8196; N_MOBA = 13,614), fathers (N_MOBA = 13,935), and offspring (N_ALSPAC=8,237; N_MOBA=14,112; N_GENR=2,661). Associations between maternal GRS and offspring risk of ADHD symptoms were tested in the full sample to avoid collider bias. Offspring GRS analyses were stratified by maternal drinking status.

Results

The pooled estimate in maternal GRS analyses adjusted for offspring GRS in ALSPAC and MoBa was OR = 0.99, 95%CI 0.97–1.02. The pooled estimate in offspring GRS analyses stratified by maternal drinking status across all the cohorts was as follows: OR_DRINKING = 0.98, 95% CI 0.94–1.02; OR_{NO DRINKING} = 0.99, 95% CI 0.97–1.02. These findings remained similar after accounting for maternal genotype data in ALSPAC and maternal and paternal genotype data in MoBa.

Conclusions

We did not find evidence for a causal effect of fetal alcohol exposure on risk of ADHD symptoms in offspring. The results may be affected by limited power to detect small effects and outcome assessment.

Characterization of alcohol polygenic risk scores in the context of mental health outcomes: Within-individual and intergenerational analyses in the Avon Longitudinal Study of Parents and Children

BACKGROUND

Heavy alcohol consumption often co-occurs with mental health problems; this could be due to confounding, shared biological mechanisms, or causal effects. Polygenic risk scores (PRS) for alcohol use can be used to explore this association at critical life stages.

DESIGN

We characterized a PRS reliably associated with patterns of adult alcohol consumption by 1) validating whether it predicts own alcohol use at different life-stages (pregnancy, adolescence) of interest for mental health impact. Additionally, we explored associations of alcohol PRS on mental health phenotypes 2) within-individuals (using own alcohol PRS on own phenotypes) and 3) intergenerationally (using maternal alcohol PRS on offspring phenotypes). We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC) (n = 960-7841). Additional substance abuse behaviors and mental health/behavioral outcomes were investigated (alcohol phenotypes n = 22; health phenotypes n = 91).

FINDINGS

Maternal alcohol PRS was associated with consumption during pregnancy (strongest signal: alcohol frequency at 18 weeks' gestation: β = 0.041, 95%CI = 0.0.02-0.06), p = 1.01 × 10-5, adjusted R2 = 1.6 %), offspring alcohol PRS did not predict offspring alcohol consumption. We found evidence for an association of maternal alcohol PRS with own perinatal depression (OR  = 1.10, 95% CI = 1.02 to 1.18, p = 0.022) and decreased offspring intellectual ability (β=-0.209, 95% CI -0.38 to -0.04, p= 0.016).

CONCLUSIONS

These alcohol PRS are a valid proxy for maternal alcohol use in pregnancy. Offspring alcohol PRS was not associated with drinking in adolescence. Consistently with results from different study designs, we found evidence that maternal alcohol PRS are associated with both prenatal depression and decreased offspring intellectual ability.

X-exome sequencing of 405 unresolved families identifies seven novel intellectual disability genes

X-linked intellectual disability (XLID) is a clinically and genetically heterogeneous disorder. During the past two decades in excess of 100 X-chromosome ID genes have been identified. Yet, a large number of families mapping to the X-chromosome remained unresolved suggesting that more XLID genes or loci are yet to be identified. Here, we have investigated 405 unresolved families with XLID. We employed massively parallel sequencing of all X-chromosome exons in the index males. The majority of these males were previously tested negative for copy number variations and for mutations in a subset of known XLID genes by Sanger sequencing. In total, 745 X-chromosomal genes were screened. After stringent filtering, a total of 1297 non-recurrent exonic variants remained for prioritization. Co-segregation analysis of potential clinically relevant changes revealed that 80 families (20%) carried pathogenic variants in established XLID genes. In 19 families, we detected likely causative protein truncating and missense variants in 7 novel and validated XLID genes (CLCN4, CNKSR2, FRMPD4, KLHL15, LAS1L, RLIM and USP27X) and potentially deleterious variants in 2 novel candidate XLID genes (CDK16 and TAF1). We show that the CLCN4 and CNKSR2 variants impair protein functions as indicated by electrophysiological studies and altered differentiation of cultured primary neurons from Clcn4(-/-) mice or after mRNA knock-down. The newly identified and candidate XLID proteins belong to pathways and networks with established roles in cognitive function and intellectual disability in particular. We suggest that systematic sequencing of all X-chromosomal genes in a cohort of patients with genetic evidence for X-chromosome locus involvement may resolve up to 58% of Fragile X-negative cases.

Whole-exome sequencing points to considerable genetic heterogeneity of cerebral palsy

Cerebral palsy (CP) is a common, clinically heterogeneous group of disorders affecting movement and posture. Its prevalence has changed little in 50 years and the causes remain largely unknown. The genetic contribution to CP causation has been predicted to be ~2%. We performed whole-exome sequencing of 183 cases with CP including both parents (98 cases) or one parent (67 cases) and 18 singleton cases (no parental DNA). We identified and validated 61 de novo protein-altering variants in 43 out of 98 (44%) case-parent trios. Initial prioritization of variants for causality was by mutation type, whether they were known or predicted to be deleterious and whether they occurred in known disease genes whose clinical spectrum overlaps CP. Further, prioritization used two multidimensional frameworks-the Residual Variation Intolerance Score and the Combined Annotation-dependent Depletion score. Ten de novo mutations in three previously identified disease genes (TUBA1A (n=2), SCN8A (n=1) and KDM5C (n=1)) and in six novel candidate CP genes (AGAP1, JHDM1D, MAST1, NAA35, RFX2 and WIPI2) were predicted to be potentially pathogenic for CP. In addition, we identified four predicted pathogenic, hemizygous variants on chromosome X in two known disease genes, L1CAM and PAK3, and in two novel candidate CP genes, CD99L2 and TENM1. In total, 14% of CP cases, by strict criteria, had a potentially disease-causing gene variant. Half were in novel genes. The genetic heterogeneity highlights the complexity of the genetic contribution to CP. Function and pathway studies are required to establish the causative role of these putative pathogenic CP genes.

Genotype and clinical care correlations in craniosynostosis: findings from a cohort of 630 Australian and New Zealand patients

Craniosynostosis is one of the most common craniofacial disorders encountered in clinical genetics practice, with an overall incidence of 1 in 2,500. Between 30% and 70% of syndromic craniosynostoses are caused by mutations in hotspots in the fibroblast growth factor receptor (FGFR) genes or in the TWIST1 gene with the difference in detection rates likely to be related to different study populations within craniofacial centers. Here we present results from molecular testing of an Australia and New Zealand cohort of 630 individuals with a diagnosis of craniosynostosis. Data were obtained by Sanger sequencing of FGFR1, FGFR2, and FGFR3 hotspot exons and the TWIST1 gene, as well as copy number detection of TWIST1. Of the 630 probands, there were 231 who had one of 80 distinct mutations (36%). Among the 80 mutations, 17 novel sequence variants were detected in three of the four genes screened. In addition to the proband cohort there were 96 individuals who underwent predictive or prenatal testing as part of family studies. Dysmorphic features consistent with the known FGFR1-3/TWIST1-associated syndromes were predictive for mutation detection. We also show a statistically significant association between splice site mutations in FGFR2 and a clinical diagnosis of Pfeiffer syndrome, more severe clinical phenotypes associated with FGFR2 exon 10 versus exon 8 mutations, and more frequent surgical procedures in the presence of a pathogenic mutation. Targeting gene hot spot areas for mutation analysis is a useful strategy to maximize the success of molecular diagnosis for individuals with craniosynostosis.

Early vocabulary in full term and preterm Estonian children

BACKGROUND

Preterm birth is considered to be a high risk factor for child development and early vocabulary can be used as an indicator for later development.

AIMS

The aim of the present study is to compare the size of early vocabulary, proportional use of different word categories, and mean length of utterance (henceforth MLU) of preterm and full term children.

METHOD

The sample consisted of 40 preterm (corrected ages 16-25 months) and two matched groups of full term children. First full term group consisted of 120 children who were matched by age and gender. Second full term group consisted of 109 children who were matched by age, gender and size of productive vocabulary. The data for this study were gathered using the Estonian adaptation of MacArthur-Bates Communicative Development Inventory: Words and Sentences.

RESULTS

Full term children who were matched by age and gender had larger vocabulary as compared to the preterm children's vocabulary (U = 1758.5, p = 0.01). Poisson regression yielded that age, gender, and preterm birth explained significantly the variance in the vocabulary size. Poisson regressions showed that all three variables explained significantly variance in proportional use of social terms and predicates. Age had significant effect for proportional use of common nouns. Age and preterm birth had a significant effect on the proportional use of function words. MLU was shorter in preterm than in full term children (U = 1125.0, p = 0.002).

CONCLUSIONS

Estonian preterm children's vocabulary is slightly smaller than full term children's vocabulary. There is a difference in the proportions of word categories used, as preterm children use more social terms, and less predicates, and function words.

Microcephalic osteodysplastic primordial dwarfism type I with biallelic mutations in the RNU4ATAC gene

Microcephalic osteodysplastic primordial dwarfism type I (MOPD I) is a rare autosomal recessive developmental disorder characterized by extreme intrauterine growth retardation, severe microcephaly, central nervous system abnormalities, dysmorphic facial features, skin abnormalities, skeletal changes, limb deformations, and early death. Recently, mutations in the RNU4ATAC gene, which encodes U4atac, a small nuclear RNA that is a crucial component of the minor spliceosome, were found to cause MOPD I. MOPD I is the first disease known to be associated with a defect in small nuclear RNAs. We describe here the clinical and molecular data for 17 cases of MOPD I, including 15 previously unreported cases, all carrying biallelic mutations in the RNU4ATAC gene.

Fetal alcohol syndrome: a prospective national surveillance study

OBJECTIVE

To describe the epidemiology of cases of fetal alcohol syndrome (FAS) seen by Australian paediatricians.

METHODS

Active, national case-finding using the Australian Paediatric Surveillance Unit (APSU). Monthly reporting of incident cases aged <15 years by paediatricians between January 2001 and December 2004.

RESULTS

Over 1150 paediatricians submitted reports each month to the APSU. Of 169 reported cases, 92 fulfilled the study criteria for FAS. There was a significant increase in the number of children reported each year from 2001 to 2004. Of 92 children, 53.3% were male, 35.7% were preterm (<37 weeks' gestation) and 64.6% were of low birth weight (<2.5 kg). Most (94.4%) had high risk exposure to alcohol in utero and 78.3% were exposed to one or more additional drugs. The median age at diagnosis was 3.3 years (range: newborn to 11.9 years): 6.5% were diagnosed at birth and 63% by 5 years of age. Of the 92 cases, 56% had growth deficiency, 53.2% had microcephaly, 85.9% had evidence of central nervous system dysfunction, 24% had additional birth defects, 5.4% had sensorineural deafness and 4.3% had visual impairment. Of children with FAS, 65% were Indigenous, 51% had a sibling with FAS, and only 40.2% lived with a biological parent.

CONCLUSION

Our data are the only prospective national data available on FAS throughout the world. These findings highlight the severity, complexity and impact of FAS, the need for effective strategies for prevention, and the necessity for education to facilitate earlier diagnosis, referral and reporting of cases.

Chronic colitis due to an epithelial barrier defect: the role of kindlin-1 isoforms

Kindlin-1 is an epithelium-specific phosphoprotein and focal adhesion adaptor component. Mutations in the corresponding gene (KIND1) cause Kindler syndrome (KS), which is manifested by skin blistering, poikiloderma, photosensitivity and carcinogenesis. Some patients also exhibit gastrointestinal symptoms, but it has remained unclear whether these represent a feature of Kindler syndrome or a coincidence. We examined kindlin-1 in human gastrointestinal epithelia and showed that it is involved in the aetiopathology of Kindler syndrome-associated colitis. Kindlin-1 expression was assessed by indirect immunofluorescence, western blot and RT-PCR. Kindlin-1 is expressed in oral mucosa, colon and rectum. Both the full-length 74 kDa kindlin-1 protein and a 43 kDa isoform were detected in CaCo2 cells, the latter resulting from alternative splicing. In the first months of life, patients (homozygous for null mutations) had severe intestinal involvement with haemorrhagic diarrhoea and showed morphological features of severe ulcerative colitis. Later in childhood, histopathology demonstrated focal detachment of the epithelium in all segments of the colon, chronic inflammation and mucosal atrophy. These findings define an intestinal phenotype for Kindler syndrome as a consequence of a primary epithelial barrier defect. The different clinical intestinal manifestations in Kindler syndrome patients may be explained by partial functional compensation of kindlin-1 deficiency by the intestinal isoform or by the presence of truncated mutant kindlin-1.

An absence of cutaneous neurofibromas associated with a 3-bp inframe deletion in exon 17 of the NF1 gene (c.2970-2972 delAAT): evidence of a clinically significant NF1 genotype-phenotype correlation

Neurofibromatosis type 1 (NF1) is characterized by cafe-au-lait spots, skinfold freckling, and cutaneous neurofibromas. No obvious relationships between small mutations (<20 bp) of the NF1 gene and a specific phenotype have previously been demonstrated, which suggests that interaction with either unlinked modifying genes and/or the normal NF1 allele may be involved in the development of the particular clinical features associated with NF1. We identified 21 unrelated probands with NF1 (14 familial and 7 sporadic cases) who were all found to have the same c.2970-2972 delAAT (p.990delM) mutation but no cutaneous neurofibromas or clinically obvious plexiform neurofibromas. Molecular analysis identified the same 3-bp inframe deletion (c.2970-2972 delAAT) in exon 17 of the NF1 gene in all affected subjects. The Delta AAT mutation is predicted to result in the loss of one of two adjacent methionines (codon 991 or 992) ( Delta Met991), in conjunction with silent ACA-->ACG change of codon 990. These two methionine residues are located in a highly conserved region of neurofibromin and are expected, therefore, to have a functional role in the protein. Our data represent results from the first study to correlate a specific small mutation of the NF1 gene to the expression of a particular clinical phenotype. The biological mechanism that relates this specific mutation to the suppression of cutaneous neurofibroma development is unknown.

Frequency of truly cryptic subtelomere abnormalities--a study of 534 patients and literature review

Frequency of truly cryptic subtelomere abnormalities - a study of 534 patients and literature review. Unbalanced subtelomere chromosome rearrangements are a significant cause of mental retardation with approximately 5% of over 3000 affected individuals tested worldwide having a chromosome rearrangement of this type. Many of these abnormalities are detectable using routine karyotyping at the 550 band level and therefore are not considered to be cryptic. The frequency of truly cryptic subtelomere abnormality should be less than 5% but has not been established. In this study, we defined 'cryptic abnormality' as one not detectable at the 550 band level on routine karyotyping. Using this as one of the selection criteria, we have studied 534 individuals with mental retardation/ developmental delay (MR/DD) and referred for subtelomere study by clinical geneticists. We have identified seven cases with cryptic subtelomere abnormalities. The clinical features of the seven abnormal cases are summarized. Literature review identified five publications on the identification of subtelomere abnormalities which used similar recruitment criteria: (a) normal karyotype at the 550 band level and (b) subjects were selected for subtelomere studies. Combining the data from these studies with those of the current study, 1154 patients were tested and 30 subtelomere abnormalities were identified. We estimate the frequency of truly cryptic subtelomere abnormality to be approximately 2.6% (30/1154) in children with MR/DD who are referred for subtelomere study.

A South Australian population-based study of congenital talipes equinovarus

The aims of this study were to provide a population-based prevalence for congenital talipes equinovarus (CTEV), to conduct an epidemiological investigation into the risk factors for CTEV and describe associated features. The study used a retrospective case-control design of CTEV notified to the South Australian Birth Defects Register between 1986 and 1996 inclusive, linking characteristics of mother and baby from the perinatal data collection. The prevalence of isolated CTEV was 1.1/1000 total births (n = 231). Four factors were significantly associated with an increased risk of CTEV: maternal Aboriginal race (ORadj = 2.0; 95% CI 1.1, 3.6), male gender (ORadj = 2.4; 95% CI 1.8, 3.2), maternal anaemia (ORadj = 1.8; 95% CI 1.0, 2.9) and maternal hyperemesis (ORadj = 3.6; 95% CI 1.3, 9.8). The prevalence of CTEV associated with another birth defect or syndrome (n = 157) was 0.7/1000 total births. CTEV was associated with specific birth defects and also with oligohydramnios when another birth defect was present.

The Hunter-McAlpine syndrome results from duplication 5q35-qter

In 1977 Hunter et al. J Med Genet 1977: 14 (6): 430-437, reported a family with six affected members, connected over three generations through unaffected individuals. Subsequently, several other patients purported to have the condition were reported. The condition became known as the Hunter-McAlpine syndrome, and there was debate as to whether or not it was identical to the Ruvalcaba syndrome or a type of tricho-rhino-phalangeal syndrome. In this article we confirm that the original family and a patient reported by Ades et al. Clin Dysmorphol 1993: 2 (2): 123-130 have cryptic translocations resulting in duplication of 5q35-qter. Similarities are noted between our patients and others in the literature with duplication of this chromosome segment.

Communication and information-giving in high-risk breast cancer consultations: influence on patient outcomes

This longitudinal study aimed to document (i) the information-giving and patient-communication styles of clinical geneticists and genetic counsellors (consultants) in familial breast cancer clinics and (ii) assess the effect of these styles on women's knowledge, whether their expectations were met, satisfaction, risk perception and psychological status. A total of 158 women from high-risk breast cancer families completed self-report questionnaires at 2 weeks preconsultation and 4 weeks postconsultation. The consultations were audiotaped, transcribed and coded. Multivariate logistic regressions showed that discussing prophylactic mastectomy (P=0.00) and oophorectomy (P=0.01) led to women having significantly more expectations met; discussing genetic testing significantly decreased anxiety (P=0.03) and facilitating understanding significantly decreased depression (P=0.05). Receiving a summary letter of the consultation significantly lowered anxiety (P=0.01) and significantly increased the accuracy of perceived risk (P=0.02). Women whose consultant used more supportive communications experienced significantly more anxiety about breast cancer at the 4 weeks follow-up (P=0.00). These women were not significantly more anxious before genetic counselling. In conclusion, this study found that consultants vary in the amount of information they give and the way they communicate; and this variation can result in better or worse psychosocial outcomes. Greater use of supportive and counselling communications appeared to increase anxiety about breast cancer. Identifying methods to assist consultants to address emotional issues effectively may be helpful.

SUMO-1 marks the nuclear inclusions in familial neuronal intranuclear inclusion disease

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder characterized by progressive ataxia and neuronal nuclear inclusions (NIs), similar to the inclusions found in expanded CAG repeat diseases. NIID may be familial or sporadic. The cause of familial NIID is poorly understood, as no CAG expansion has been detected. We examined three cases, from two unrelated families, who had autosomal dominant NIID but normal CAG repeats in genes involved in polyglutamine neurodegenerative diseases. We found that NIs in all three cases were intensely immunopositive for SUMO-1, a protein which covalently conjugates to other proteins and targets them to the nuclear regions (nuclear bodies) responsible for nuclear proteasomal degradation. Electron microscopy demonstrated that SUMO-1 was located on the 10-nm fibrils of NIs. In cultured PC12 cells, we found that inhibition of proteasome function by specific inhibitors resulted in the appearance of SUMO-1-immunopositive nuclear inclusions. Our study suggests that recruitment of SUMO-1 modified proteins into insoluble nuclear inclusions and proteasomal dysfunction may be involved in the pathogenesis of NIs in familial NIID cases.

Growth, behavior, and clinical findings in 27 patients with Kabuki (Niikawa-Kuroki) syndrome

This study was undertaken to document the phenotype of Kabuki (Niikawa-Kuroki) syndrome in patients from Australia and New Zealand, with particular emphasis on growth patterns, behavior, and relationship between head circumference and intellectual level. Data on 27 children and adults with Kabuki (Niikawa-Kuroki) syndrome from Australia and New Zealand were collected by questionnaire and clinical assessment. The patients ranged in age from 7 months to 36 years with a mean age of 7 years and 2 months. The mean age at diagnosis was 3(5/6) years, but in most cases, the facial phenotype was evident from infancy. The minimum birth prevalence was calculated at 1 in 86,000. Three of our patients died. Parents reported a behavior phenotype characterized by an excellent long-term memory and avoidance of eye contact. No correlation was found between head circumference and severity of intellectual disability. Eight of 14 patients over the age of 5 years were overweight or obese. Six of these eight patients had failure to thrive in infancy. One patient developed insulin-dependent diabetes mellitus in adolescence. Some individuals with Kabuki (Niikawa-Kuroki) syndrome show a characteristic growth profile with failure to thrive in infancy progressing to obesity or overweight in middle childhood or adolescence. A behavior phenotype was noted which requires further investigation. Head size is not a predictor of degree of intellectual disability.

X-linked myotubular myopathy in a family with three adult survivors

We describe a family with an extremely mild form of X-linked myotubular myopathy. Three affected males survived to adulthood with sufficient muscle strength to enable them to carry out normal daily activities. The mildness of the myopathy in this family is highlighted by the following: no neonatal or infant mortality resulting from the myopathy; one affected male who did not have neonatal asphyxia and had normal early motor milestones - this affected male was able to increase his muscle bulk and strength to normal by weightlifting; and a 55-year-old male who still lives an independent life. DNA sequencing identified a novel missense mutation - G469A (E157K) - in exon 7 of the MTM1 gene in this family. To our knowledge, this is the third X-linked myotubular myopathy family, with multiple adult survivors, to be reported in the literature.

Birth prevalence of Prader-Willi syndrome in Australia

This is the first population based study to estimate the birth prevalence of DNA proven Prader-Willi syndrome. Thirty infants were reported to the Australian Paediatric Surveillance Unit between 1998 and 2000, a prevalence of 4 per 100,000 live births or approximately 1/25,000 live births per annum.

Principal mutation hotspot for central core disease and related myopathies in the C-terminal transmembrane region of the RYR1 gene

The congenital myopathies are a group of disorders characterised by the predominance of specific histological features observed in biopsied muscle. Central core disease and nemaline myopathy are examples of congenital myopathies that have specific histological characteristics but significantly overlapping clinical pictures. Central core disease is an autosomal dominant disorder with variable penetrance which has been linked principally to the gene for the skeletal muscle calcium release channel (RYR1). Two recent reports have identified the 3' transmembrane domain of this gene as a common site for mutations. Two other studies have reported single families that have features of both central core disease and nemaline myopathy (core/rod disease) caused by mutations in RYR1. Screening of the 3' region (exons 93-105) of the RYR1 gene for mutations in 27 apparently unrelated patients with either central core disease or core/rod disease by single strand conformation polymorphism analysis and DNA sequencing identified three described and nine novel mutations in 15 patients.

"Folate before pregnancy": the impact on women and health professionals of a population-based health promotion campaign in South Australia

OBJECTIVES

To evaluate a South Australian campaign to promote and implement knowledge that taking adequate folate/folic acid in the periconceptional period can reduce the risk of having a baby with a neural tube defect.

DESIGN AND SETTING

The campaign, conducted in October 1994--August 1995, targeted women of reproductive age and health professionals. Evaluation was by computer-assisted telephone interviews undertaken by random dialling throughout the State before and after the campaign, and by self-administered questionnaires to health professionals and women in the postnatal period.

PARTICIPANTS

Women of reproductive age and four groups of health professionals.

MAIN OUTCOME MEASURES

Knowledge about folate, folate-rich foods and the periconceptional period; participation of health professionals in advising women about folate; use of periconceptional folic acid supplements; sales of folic acid tablets; and prevalence of neural tube defects.

RESULTS

Significant increases in knowledge about folate followed the campaign. Health professionals and women in the postnatal period had higher initial levels of knowledge about folate, which also increased significantly. The proportions of women taking periconceptional folic acid supplements, and of health professionals advising women planning a pregnancy about folate, also increased significantly, and folic acid tablet sales doubled. Total prevalence of neural tube defects declined between 1966 and 1999 from a baseline of 2.0 per 1,000 births to 1.1 per 1,000 births (Poisson regression, P= 0.03; average decline of 1.0% per year).

CONCLUSIONS

A short educational campaign with a limited budget ($40,000) can promote folate successfully, but alternative strategies such as food fortification are likely to be needed to achieve adequate periconceptional folate intake for a very high proportion of women.

Sustained virological response in chronic hepatitis C patients after a 6- and a 36-month interferon-alpha2b treatment schedule: a multicenter, randomized, controlled study

BACKGROUND

In patients with chronic hepatitis C (HCV) Interferon-alpha (IFN) treatment for 12-18 months is more effective than 6 months in inducing a sustained virological response.

METHODS

In a multicenter, randomized, controlled trial, 88 patients with chronic HCV were enrolled (47 treated with IFN-alpha2b and 41 constituted an untreated control group). Treatment consisted of 5 million units (MU) IFN thrice a week (tiw) for 8 weeks and subsequently 2.5 MU IFN tiw for 16 weeks ('standard treatment'). After week 24 ('long-term treatment'), in virological non-responders treatment was continued using 5 MU IFN tiw for up to week 156, whereas in virological responders IFN was discontinued. In case of a virological relapse, treatment with 5 MU IFN tiw was restarted and continued up to week 156.

RESULTS

Sustained virological response rate was 6/47 (13%) after standard treatment and increased to 19/47 (40%) after long-term treatment (McNemar paired test; P = 0.002). Of the 18 patients with a breakthrough or relapse during or after standard treatment, 14 (78%) became sustained virological responders upon long-term treatment. Of the 4 patients who did not have a sustained virological response after long-term treatment, 3 did not receive complete treatment due to side effects and/or non-compliance. In patients who failed to respond to standard treatment, no virological response was observed during long-term treatment. In the control group, no spontaneous clearance of HCV was observed.

CONCLUSIONS

Long-term IFN (re)treatment enhanced the virological sustained response rate significantly and was particularly effective in patients with a breakthrough or relapse following standard treatment.

New mutations in MID1 provide support for loss of function as the cause of X-linked Opitz syndrome

Opitz syndrome (OS) is a genetically heterogeneous malformation disorder. Patients with OS may present with a variable array of malformations that are indicative of a disturbance of the primary midline developmental field. Mutations in the C-terminal half of MID1, an RBCC (RING, B-box and coiled-coil) protein, have recently been shown to underlie the X-linked form of OS. Here we show that the MID1 gene spans at least 400 kb, almost twice the distance originally reported and has a minimum of six mRNA isoforms as a result of the alternative use of 5' untranslated exons. In addition, our detailed mutational analysis of MID1 in a cohort of 15 patients with OS has resulted in the identification of seven novel mutations, two of which disrupt the N-terminus of the protein. The most severe of these (E115X) is predicted to truncate the protein before the B-box motifs. In a separate patient, a missense change (L626P) was found that also represents the most C-terminal alteration reported to date. As noted with other C-terminal mutations, GFP fusion constructs demonstrated that the L626P mutant formed cytoplasmic clumps in contrast to the microtubular distribution seen with the wild-type sequence. Notably, however, both N-terminal mutants showed no evidence of cytoplasmic aggregation, inferring that this feature is not pathognomonic for X-linked OS. These new data and the finding of linkage to MID1 in the absence of a demonstrable open reading frame mutation in a further family support the conclusion that X-linked OS results from loss of function of MID1.

Acampomelic campomelic dysplasia with SOX9 mutation

Acampomelic campomelic dysplasia is a rare clinical variant of the more commonly encountered campomelic dysplasia (CMD1), characterized by absence of long bone curvature (acampomelia). We present a patient with acampomelic CMD1 with a de novo SOX9 missense mutation and report his clinical course to age one year, thereby contributing to genotype-phenotype correlation in CMD1. 2000.

Intention to undergo prophylactic bilateral mastectomy in women at increased risk of developing hereditary breast cancer

PURPOSE

To assess intention to undergo prophylactic bilateral mastectomy and psychologic determinants in unaffected women at increased risk of developing hereditary breast cancer.

PATIENTS AND METHODS

Three hundred thirty-three women who were awaiting their initial appointments for risk assessment, advice about surveillance, and prophylactic options at one of 14 familial cancer clinics participated in a cross-sectional, questionnaire-based survey.

RESULTS

Nineteen percent of women would consider and 47% would not consider a prophylactic mastectomy, should genetic testing identify a mutation in a breast cancer-predisposing gene, whereas 34% were unsure and 1% had already undergone a prophylactic mastectomy. In a bivariate analysis, women at a moderately increased risk of developing breast cancer had the highest proportion of subjects reporting that they would consider a prophylactic mastectomy (25%), compared with women at high risk (16%) (chi(2) = 7.79; P =.051). In multivariate analyses, consideration of prophylactic mastectomy strongly correlated with high levels of breast cancer anxiety (odds ratio [OR] = 17.4; 95% confidence interval [CI], 4.35 to 69.71; P =. 0001) and overestimation of one's breast cancer risk (OR = 3.01; 95% CI, 1.43 to 6.32; P =.0036), whereas there was no association with objective breast cancer risk (P =.60).

CONCLUSION

A significant proportion of women at increased risk of developing hereditary breast cancer would consider prophylactic mastectomy. Although prophylactic mastectomy may be appropriate in women at high risk of developing breast cancer, it is perhaps less so in those who have a moderately increased risk. Such moderate-risk women are likely to benefit from interventions aimed at reducing breast cancer anxiety and correcting exaggerated breast cancer risk perceptions.

Breast cancer screening uptake in women at increased risk of developing hereditary breast cancer

This multicenter study assessed breast cancer screening uptake in 461 unaffected women at increased risk of developing breast cancer on the basis of family history who approached familial cancer clinics for advice about surveillance options. At the time of attending the clinic, 89% and 90% of participants were vigilant with respect to age- and risk-specific recommendations for mammography and clinical breast examination, respectively, and 51% reported practicing breast self-examination monthly or more frequently. The degree to which health outcomes are perceived to be under one's personal control (chi2 = -2.09, p = 0.0037) and breast cancer anxiety (chi2 = 8.11, p = 0.044) were both associated with monthly or more frequent breast self-examination, while there were no associations with sociodemographic characteristics. A significantly lower percentage (56%) of women aged <30 were vigilant with respect to mammography recommendations, compared to 77%, 96% and 98% of women aged 30-39, 40-49 and >50, respectively (chi2 = 37.2, p < 0.0001). These relatively low rates of mammographic screening in young women may reflect concerns about increased cancer risk associated with early and repeated radiation exposure or lack of sensitivity in young women with radiographically dense breasts. If mammographic screening is ultimately shown to lower mortality in women at high risk, there will be a strong case to promote screening in young women. The need for regular mammographic screening would then need to be highlighted and reinforced amongst young women and their referring physicians. Awareness amongst general practitioners, who are largely responsible for referral to screening services, would also need to be increased.

The half-life of infused factor VIII is shorter in hemophiliac patients with blood group O than in those with blood group A

A considerable inter-individual variation in half-life of infused factor VIII is observed among patients with hemophilia A. The factors contributing to this wide range in factor VIII half-life are not known in detail. We analysed the pharmacokinetics of infused factor VIII in 32 patients with hemophilia A, comprising 20 brothers from 10 families, 3 and 4 brothers from 2 families, and 5 patients from 5 single families, respectively. Multiple linear regression analysis was used to assess the effect of several variables on factor VIII half-life. We found that the pre-infusion von Willebrand factor antigen levels (vWF:Ag) were positively correlated with factor VIII half-life (r = 0.52, p = 0.002), i.e., each variable was associated with about 27% of the variance of the other. In fraternal pairs, familial clustering was significant for ABO blood group (p < 0.001), but could not be detected for factor VIII half-lives or pre-infusion vWF:Ag levels. vWF:Ag level (p = 0.001) and ABO blood group (p = 0.003) significantly determined factor VIII half-life, whereas age, length, bodyweight, the presence or absence of a factor VIII gene inversion, and Rhesus phenotype did not. Patients with blood group O exhibited a statistically significant shorter factor VIII half-life than patients with blood group A (15.3 versus 19.7 h, respectively) (p = 0.003). Patients with blood group A and O differ in respect to the presence of anti-A antibodies in the latter. It is possible that these anti-A antibodies interact with endogenous vWF, thus affecting the half-life time of the factor VIII/vWF complex.

A child with hemimegalencephaly, hemihypertrophy, macrocephaly, cutaneous vascular malformation, psychomotor retardation and intestinal lymphangiectasia--a diagnostic dilemma

Although the clinical delineation of the majority of overgrowth syndromes is straightforward, we believe there is a subset of patients with overlapping features from a number of overgrowth syndromes. We report a patient with hemimegalencephaly, hemihypertrophy, macrocephaly, vascular lesions, psychomotor retardation and intestinal lymphangiectasia. The clinical history and findings posed a diagnostic dilemma as the features overlapped between several conditions, namely macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC), Klippel-Trenaunay-Weber syndrome (KTWS), Proteus syndrome and a provisional unique syndrome described by Reardon et al. (1996, Am J Med Genet 66:144-149). We anticipate that only when the molecular basis is delineated will it become clear whether these disorders are separate entities or merely differing ends of the same spectrum.

X-inactivation and marker studies in three families with incontinentia pigmenti: implications for counselling and gene localisation

Familial incontinentia pigmenti (IP) is an X-linked dominant disorder with an extremely variable clinical presentation. Ambiguous diagnosis can complicate genetic counselling and attempts to refine the gene location in Xq28. Marked skewing of X-inactivation patterns is a hallmark of IP and provides a means for investigating uncertain cases. We have conducted X-inactivation studies in three families where Xq28 marker studies were at odds with the original clinical assessment. The results indicate that no recombination between the disease locus and Xq28 loci has occurred and suggest that mosaicism is responsible for the discrepancy in one family.

Preferential pre-mRNA utilisation of an upstream cryptic 5' splice site created by a single base deletion mutation in exon 37 of the FBN-1 gene

A heterozygous deletion of a single base (A4704) from exon 37 of the fibrillin-1 gene was defined in a patient with Marfan syndrome and subsequently in his previously undiagnosed father. The deletion created a cryptic 5' splice site in exon 37 which was utilised in preference to the normal 5' splice site during pre-mRNA processing in skin fibroblasts cultured from the proband. The mutant mRNA showed a 48-bp deletion from the 3' end of exon 37 which was predicted to restore the reading frame in the mutant mRNA and result in the deletion of a 16-amino-acid sequence from a central eight-cysteine repeat motif of the fibrillin-1 molecule. Interestingly, the cryptic 5' splice site in exon 37 and the normal 5' splice site had equally strong consensuses for splice-site selection. The preferential utilisation of the cryptic site is discussed in relation to current theories on the mechanisms involved in pre-mRNA splicing. Analysis by reverse-transcription PCR indicated that, in the patients skin fibroblasts, the steady-state level of the mis-spliced mutant mRNA was close to that from the normal allele. In addition, evidence from immunoblotting and pulse-chase biosynthetic labelling indicated that close to normal amounts of fibrillin-1 were being synthesised and secreted by the cells. However, in contrast to control cells cultured from an unaffected individual, little fibrillin-1 was detected, either biosynthetically or by immunofluorescence, in the extracellular matrix produced by the proband's fibroblasts. Thus, the slightly shorter mutant fibrillin-1 molecules appeared to be exerting a powerful dominant-negative effect on the incorporation of normal fibrillin-1 molecules into microfibrils in this culture system. This severe inhibition of microfibril synthesis in cell culture contrasts with the 'classic' phenotype of the proband, suggesting that factors influencing microfibril formation may differ greatly between in vivo and in vitro environments.

What constitutes cerebral palsy?

Cerebral palsy (CP) is a term of convenience applied to a group of motor disorders of central origin defined by clinical description. It is not a diagnosis in that its application infers nothing about pathology, aetiology, or prognosis. It is an umbrella term covering a wide range of cerebral disorders which result in childhood motor impairment. The precise inclusion criteria vary with the objectives for using the term. For meaningful comparison of rates of CP, as performed by and between CP registers, it is important that the rates should be generated using the same criteria. As generally understood there must be motor impairment, and this impairment must stem from a malfunction of the brain (rather than spinal cord or muscles). Furthermore, the brain malfunction must be non-progressive and it must be manifest early in life. For the purposes of comparisons of rates across time even when the condition meets all the above criteria, it must not historically have been excluded from the category of CP. This paper addresses the problem of standardizing the inclusion criteria for selecting people included on CP registers with particular reference to this last criterion.