Denis Viljoen

Validation of a new biomarker of fetal exposure to alcohol

OBJECTIVE To test the sensitivity and specificity of fatty acid ethyl esters (FAEEs) extracted from meconium to identify alcohol-using pregnant women with a sensitive and specific methodology, gas chromatography-tandem mass spectroscopy (GC/MS/MS). Study design Twenty-seven samples of meconium were obtained from infants from the mixed race community in Cape Town, South Africa, who were enrolled in a longitudinal neurobehavioral study. Maternal alcohol use was reported prospectively during pregnancy. FAEEs were isolated from meconium and quantitated by GC/MS/MS. RESULTS Ethyl oleate was the FAEE that correlated most strongly with maternal self-reported drinking, especially with the average ounces of absolute alcohol ingested per drinking day. Ethyl oleate was most strongly related to drinking in the second and third trimesters (Pearson r=.55 and.40, respectively). At a threshold of 1.5 average ounces of absolute alcohol ingested per drinking day, the area under the receiving operator characteristic curve was.92 (95% confidence interval, 0.74-0.97). Using a cut-off value of 32 ng/g, sensitivity was 84.2% and specificity was 83.3%. CONCLUSIONS Ethyl oleate concentration in meconium assayed by GC/MS/MS provides a highly sensitive and specific indicator of maternal alcohol use during pregnancy.

Mutation Detection in the ABCC6 Gene and Genotype-Phenotype Analysis in a Large International Case Series Affected by Pseudoxanthoma Elasticum

Background: Pseudoxanthoma elasticum (PXE), an autosomal recessive disorder with considerable phenotypic variability, mainly affects the eyes, skin and cardiovascular system, characterised by dystrophic mineralization of connective tissues. It is caused by mutations in the ABCC6 (ATP binding cassette family C member 6) gene, which encodes MRP6 (multidrug resistance-associated protein 6). Objective: To investigate the mutation spectrum of ABCC6 and possible genotype–phenotype correlations. Methods: Mutation data were collected on an international case series of 270 patients with PXE (239 probands, 31 affected family members). A denaturing high-performance liquid chromatography-based assay was developed to screen for mutations in all 31 exons, eliminating pseudogene coamplification. In 134 patients with a known phenotype and both mutations identified, genotype–phenotype correlations were assessed. Results: In total, 316 mutant alleles in ABCC6, including 39 novel mutations, were identified in 239 probands. Mutations were found to cluster in exons 24 and 28, corresponding to the second nucleotide-binding fold and the last intracellular domain of the protein. Together with the recurrent R1141X and del23–29 mutations, these mutations accounted for 71.5% of the total individual mutations identified. Genotype–phenotype analysis failed to reveal a significant correlation between the types of mutations identified or their predicted effect on the expression of the protein and the age of onset and severity of the disease. Conclusions: This study emphasises the principal role of ABCC6 mutations in the pathogenesis of PXE, but the reasons for phenotypic variability remain to be explored.

Universal prevention is associated with lower prevalence of fetal alcohol spectrum disorders in Northern Cape South Africa: a multicentre before-after study.

AIMS Prevalence of fetal alcohol spectrum disorders (FASDs) is remarkably high in several provinces of South Africa; yet population-level knowledge of the harms of maternal drinking remains low. In two heavily affected areas, we assessed effectiveness of interventions to heighten awareness of these harms and to alter social norms about drinking in pregnancy. METHODS FASD prevalence, maternal knowledge and drinking behaviours were investigated in two Northern Cape Province towns, before and after interventions which included highlighting FASD using local media and health promotion talks at health facilities. Independently, two dysmorphologists and a neuropsychometrist examined children at 9 and 18 months. RESULTS Pre-intervention maternal knowledge of alcohol harms was low and FASD prevalence 8.9% (72/809). Interventions reached high coverage and knowledge levels increased substantially. FASD prevalence was 5.7% post-intervention (43/751; P = 0.02); 0.73 lower odds, controlling for maternal age and ethnicity (95% confidence interval = 0.58-0.90). No change was detected in more severe FASD forms, but in the whole population, median dysmorphology scores reduced from 4 [inter-quartile range (IQR) = 2-7] to 3 (IQR = 1-6; P = 0.002). CONCLUSION This, the first prevention study using FASD outcomes, suggests that universal prevention might reduce FASD by ∼30% and have population-level effects. This supports intensifying universal interventions where knowledge of harms of maternal drinking is low. These efforts need to be accompanied by alcohol-dependence treatment to lower more severe FASD forms.

Reduced DNA methylation at the PEG3 DMR and KvDMR1 loci in children exposed to alcohol in utero: a South African Fetal Alcohol Syndrome cohort study.

Fetal alcohol syndrome (FAS) is a devastating developmental disorder resulting from alcohol exposure during fetal development. It is a considerable public health problem worldwide and is characterized by central nervous system abnormalities, dysmorphic facial features, and growth retardation. Imprinted genes are known to play an important role in growth and development and therefore four imprinting control regions (ICRs), H19 ICR, IG-DMR, KvDMR1 and PEG3 DMR were examined. It is proposed that DNA methylation changes may contribute to developmental abnormalities seen in FAS and which persist into adulthood. The participants included FAS children and controls from the Western and Northern Cape Provinces. DNA samples extracted from blood and buccal cells were bisulfite modified, the ICRs were amplified by PCR and pyrosequencing was used to derive a quantitative estimate of methylation at selected CpG dinucleotides: H19 ICR (six CpG sites; 50 controls and 73 cases); KvDMR1 (7, 55, and 86); IG-DMR (10, 56, and 84); and PEG3 DMR (7, 50, and 79). The most profound effects of alcohol exposure are on neuronal development. In this study we report on epigenetic effects observed in blood which may not directly reflect tissue-specific alterations in the developing brain. After adjusting for age and sex (known confounders for DNA methylation), there was a significant difference at KvDMR1 and PEG3 DMR, but not the H19 ICR, with only a small effect (0.84% lower in cases; p = 0.035) at IG-DMR. The two maternally imprinted loci, KvDMR1 and PEG3 DMR, showed lower average locus-wide methylation in the FAS cases (1.49%; p < 0.001 and 7.09%; p < 0.001, respectively). The largest effect was at the PEG3 DMR though the functional impact is uncertain. This study supports the role of epigenetic modulation as a mechanism for the teratogenic effects of alcohol by altering the methylation profiles of imprinted loci in a locus-specific manner.

Developmental delay of infants and young children with and without fetal alcohol spectrum disorder in the Northern Cape Province, South Africa

OBJECTIVE To describe the extent and nature of developmental delay at different stages in childhood in a community in South Africa, with a known high rate of Fetal Alcohol Spectrum Disorder (FASD). METHOD cohort of infants, clinically examined for FASD at two time periods, 7-12 months (N= 392; 45 FASD) and 17-21 months of age (N = 83, 35 FASD) were assessed using the Griffiths Mental Developmental Scales (GMDS). RESULTS Infants and children with FASD perform worse than their Non-FASD counterparts over all scales and total developmental quotients. Mean quotients for both groups decline between assessments across subscales with a particularly marked decline in the hearing and language scale at Time 2 (scores dropping from 110.6 to 83.1 in the Non-FASD group and 106.3 to 72.7 in the FASD group; P = 0.004). By early childhood the developmental gap between the groups widens with low maternal education, maternal depression, high parity and previous loss of sibling/s influencing development during early childhood. CONCLUSION The FASD group show more evidence of developmental delay over both time points compared to their Non-FASD counterparts. Demographic and socio-economic factors further impact early childhood. These findings are important in setting up primary level psycho-educational and national prevention programmes especially in periurban communities with a focus on early childhood development and FASD.

Fetal alcohol spectrum disorders: Prevalence rates in South Africa.

BACKGROUND Fetal alcohol spectrum disorder (FASD) is an under-diagnosed condition in South Africa (SA). Fetal alcohol syndrome and FASD community prevalence studies were undertaken in 17 towns in three of the nine provinces in SA. OBJECTIVE The objective for all the studies was to determine the FASD prevalence rates by assessing the grade 1 learners in all the studies, using international FASD diagnostic criteria. METHODS The same methodology was used for all the studies in Gauteng, Western and Northern Cape provinces. Consenting grade 1 learners received anthropometric screening, clinical examinations and neurodevelopmental assessments. Structured interviews were used to assess maternal alcohol consumption during pregnancy. RESULTS Reported prevalence rates ranged from 29 to 290 per 1 000 live births. CONCLUSION FASD rates from studies conducted in SA are among the highest worldwide. FASD affects all communities in SA and is therefore a major public health concern in SA. Multidisciplinary and intersectoral interventions are urgently required to raise awareness about the dangers of prenatal alcohol exposure and the devastating effect of FASD on the lives of children, families and communities.

Changes in drinking patterns during and after pregnancy among mothers of children with fetal alcohol syndrome: A study in three districts of South Africa

BACKGROUND Mixed ancestry populations in South Africa have amongst the highest rates of fetal alcohol syndrome (FAS) worldwide. Defining the drinking patterns of women with a FAS child guides FAS preventive interventions. METHODS Data were drawn from FAS prevalence surveys conducted in three districts: Witzenberg (Cape Winelands), Frances Baard (inland mining town) and Saldanha Bay (coastal towns). 156 mothers and 50 proxy informants of school-entry children diagnosed with FAS and partial-FAS were interviewed, and compared with 55 controls recruited in Saldanha Bay. RESULTS Study participants were of low socio-economic status (SES), and a majority of children were either in foster care (12%) or had been cared for by relatives for long periods (44%). Of cases, 123/160 (77%) reported current drinking, similar between sites. During pregnancy, only 35% (49/139) of cases had stopped drinking, varying between sites (from 21% to 54% in chronological order of surveys; p<0.001), while 6% (7/109) increased drinking. Though many women who stopped in pregnancy resumed postpartum, cessation in pregnancy was strongly associated with discontinuation in the long run (OR=3.3; 95%CI=1.2-8.9; p=0.005). At interview, 36% of cases (54/151) and 18% of controls (9/51) were at risk of an alcohol-exposed pregnancy (p=0.02). Median maternal mass of cases was 22kg lower than controls, with 20% being underweight and 14% microcephalic. CONCLUSIONS Increasing rates of drinking cessation during pregnancy over time suggest rising awareness of FAS. Cessation is associated with recidivism after pregnancy but also with reduced long-term drinking. Interventions should target alcohol abstinence in pregnancy, but extend into the puerperium.

Osteogenesis imperfecta type 3 in South Africa: Causative mutations in FKBP10

BACKGROUND A relatively high frequency of autosomal recessively inherited osteogenesis imperfecta (OI) type 3 (OI-3) is present in the indigenous black southern African population. Affected persons may be severely handicapped as a result of frequent fractures, progressive deformity of the tubular bones and spinal malalignment. OBJECTIVE To delineate the molecular basis for the condition. METHODS Molecular investigations were performed on 91 affected persons from seven diverse ethnolinguistic groups in this population. RESULTS Following polymerase chain reaction amplification and direct cycle sequencing, FKBP10 mutations were identified in 45.1% (41/91) OI-3-affected persons. The homozygous FKBP10 c.831dupC frameshift mutation was confirmed in 35 affected individuals in the study cohort. Haplotype analysis suggests that this mutation is identical among these OI-3-affected persons by descent, thereby confirming that they had a common ancestor. Compound heterozygosity of this founder mutation was observed, in combination with three different deleterious FKBP10 mutations, in six additional persons in the cohort. Four of these individuals had the c.831delC mutation. CONCLUSION The burden of the disorder, both in frequency and severity, warrants the establishment of a dedicated service for molecular diagnostic confirmation and genetic management of persons and families with OI in southern Africa.

Alcohol exposure during pregnancy altered childhood developmental trajectories in a rural South African community

This study examined the effects of prenatal alcohol exposure on childhood development trajectories in a rural South African community between 2003 and 2008.