Clinical delineation, sex differences, and genotype-phenotype correlation in pathogenic KDM6A variants causing X-linked Kabuki syndrome type 2.

PURPOSE: The variant spectrum and the phenotype of X-linked Kabuki syndrome type 2 (KS2) are poorly understood. METHODS: Genetic and clinical details of new and published individuals with pathogenic KDM6A variants were compiled and analyzed. RESULTS: Sixty-one distinct pathogenic KDM6A variants (50 truncating, 11 missense) from 80 patients (34 males, 46 females) were identified. Missense variants clustered in the TRP 2, 3, 7 and Jmj-C domains. Truncating variants were significantly more likely to be de novo. Thirteen individuals had maternally inherited variants and one had a paternally inherited variant. Neonatal feeding difficulties, hypoglycemia, postnatal growth retardation, poor weight gain, motor delay, intellectual disability (ID), microcephaly, congenital heart anomalies, palate defects, renal malformations, strabismus, hearing loss, recurrent infections, hyperinsulinism, seizures, joint hypermobility, and gastroesophageal reflux were frequent clinical findings. Facial features of over a third of patients were not typical for KS. Males were significantly more likely to be born prematurely, have shorter stature, and severe developmental delay/ID. CONCLUSION: We expand the KDM6A variant spectrum and delineate the KS2 phenotype. We demonstrate that the variability of the KS2 phenotypic depends on sex and the variant type. We also highlight the overlaps and differences between the phenotypes of KS2 and KS1.

Hyperphosphatasia with mental retardation syndrome type 4 in three unrelated South African patients.

Hyperphosphatasia with mental retardation syndrome (HPMRS) is a rare autosomal recessive disorder caused by pathogenic variants in genes involved in glycosylphosphatidylinositol metabolism that result in a similar phenotype. We describe the first three patients with HPMRS from sub-Saharan Africa. Detection was assisted by Face2Gene phenotype matching and confirmed by the presence of elevated serum alkaline phosphatase. All three patients had severe intellectual disability, absent speech, hypotonia and palatal abnormality (cleft palate in two, very high-arched palate in one), no or minimal brachytelephalangy, and high serum alkaline phosphatase levels. Additional findings included seizures in two, and brain imaging abnormalities in two. In all three patients HPMRS was a top-20 gestalt match using Face2Gene. The overall phenotype is consistent with descriptions in the literature of HPMRS type 4, although not specific to it. Whole exome sequencing in the index patient and his mother detected a candidate variant in a homozygous state in the index patient (PGAP3:c.557G>C, p.Arg186Thr) and heterozygous in the mother. Further variant interpretation indicated pathogenicity. Sanger sequencing of another two patients identified the same homozygous, pathogenic variant, confirming a diagnosis of HPMRS type 4. The shared homozygous variant in apparently unrelated families, and in the absence of consanguinity, suggests the possibility of genetic drift due to a population bottleneck effect, and further research is recommended.

A South African mixed race lip/philtrum guide for diagnosis of fetal alcohol spectrum disorders.

The adverse effects of maternal alcohol use during pregnancy represent a spectrum of growth restriction, facial dysmorphology, and neurocognitive challenges in the offspring. The continuum of diagnoses is referred to as fetal alcohol spectrum disorders (FASD). Short palpebral fissures, a smooth philtrum, and a thin vermilion border of the upper lip comprise the three cardinal facial features of FASD. Early attempts to define a smooth philtrum and thin vermilion border of the upper lip were subjective. Astley and colleagues introduced a 5-point Likert-scaled lip/philtrum guide based on Caucasian North American subjects as an objective tool for the evaluation of the facial dysmorphology in FASD. This Caucasian guide has been incorporated into all current diagnostic schemes for FASD. However, broad international clinical experience with FASD indicates racial and ethnic differences with respect to the facial morphology. Because of the substantial number of children with FASD in South Africa among the Cape Coloured (mixed race) population in the Western Cape Province, we developed a specific lip/philtrum guide for that population. The guide incorporates a 45-degree view of the philtrum that enables an enhanced 3-dimensional evaluation of philtral height not possible with a frontal view alone. The guide has proven to be a more specific and sensitive tool for evaluation of the facial dysmorphology of FASD in the Cape Coloured population than the use of the previous North American Caucasian guide and points to the utility of racial and ethnic-specific dysmorphology tools in the evaluation of children with suspected FASD.

Multifaceted case management during pregnancy is associated with better child outcomes and less fetal alcohol syndrome.

BACKGROUND: Pregnant women participated in multifaceted case management (MCM) to prevent Fetal Alcohol Spectrum Disorders (FASD). METHODS: Women recruited from antenatal clinics for a longitudinal child development study were screened for alcohol use. Forty-four pregnant women were defined as high-risk drinkers on the Alcohol Use Disorder Identification Test (AUDIT) by an AUDIT score ≥8 and participated in 18 months of MCM to facilitate reduction or cessation of alcohol consumption. Forty-one women completed MCM. Fifty-five equally high-risk women who received standard antenatal care comprised the comparison/control group. Development in offspring was evaluated by a blinded interdisciplinary team of examiners through 5 years of age. RESULTS: At five years of age, more children (34%) of MCM participating women did not meet the criteria for FASD vs. non-MCM offspring (22%). Furthermore, a statistically significant (p = .01) lower proportion of MCM offspring (24%) was diagnosed with fetal alcohol syndrome (FAS) compared to controls (49%). Children of MCM participants had significantly (p < .05) better physical outcomes: lower total dysmorphology scores, larger head circumferences, longer palpebral fissures, and higher midfacial measurements. Neurodevelopment results showed mixed outcomes. While Bayley developmental scores indicated that MCM offspring were performing significantly worse on most domains through 18 months, group scores equalized and were not significantly different on Kaufman Assessment Battery neurobehavioral measures by five years. Regression analyses indicated that offspring of women who received standard antenatal care were associated with significantly more negative outcomes than MCM offspring: a diagnosis of FAS (OR = 3.2; 95% CI: 1.093-9.081), microcephaly (OR = 5.3; 95% CI: 2.1-13.5), head circumference ≤10th centile (OR = 4.3; 95%CI: 1.8-10.4), and short palpebral fissures (OR = 2.5; 95% CI: 1.0-5.8). CONCLUSION: At age five, proportionally fewer children of MCM participants qualified for a diagnosis of FAS, and proportionally more had physical outcomes indicating better prenatal brain development. Neurobehavioral indicators were not significantly different from controls by age five.KEY MESSAGESMultifaceted Case Management (MCM) was designed and employed for 18 months during the prenatal and immediate postpartum period to successfully meet multiple needs of women who had proven to be very high risk for birthing children with fetal alcohol spectrum disorders (FASD).Offspring of the women who participated in MCM were followed up through age five years and were found to have significantly better physical outcomes on multiple variables associated with fetal alcohol syndrome (FAS) and FASD, such as larger head circumferences and fewer minor anomalies, than those children born to equally at-risk women not receiving MCM.Fewer children of women receiving MCM were diagnosed with FASD than the offspring of equally-at-risk controls, and significantly (p = .01) fewer MCM offspring had FAS, the most severe FASD diagnosis.

A diffusion tensor imaging and neurocognitive study of HIV-positive children who are HAART-naïve "slow progressors".

There are few neuropsychological or neuroimaging studies of HIV-positive children with "slow progression". "Slow progressors" are typically defined as children or adolescents who were vertically infected with HIV, but who received no or minimal antiretroviral therapy. We compared 12 asymptomatic HIV-positive children (8 to 12 years) with matched controls on a neuropsychological battery as well as diffusion tensor imaging in a masked region of interest analysis focusing on the corpus callosum, internal capsule and superior longitudinal fasciculus. The "slow progressor" group performed significantly worse than controls on the Wechsler Abbreviated Scale of Intelligence Verbal and Performance IQ scales, and on standardised tests of visuospatial processing, visual memory and executive functioning. "Slow progressors" had lower fractional anisotropy (FA), higher mean diffusivity (MD) and radial diffusivity (RD) in the corpus callosum (p= <0.05), and increased MD in the superior longitudinal fasciculus, compared to controls. A correlation was found between poor performance on a test of executive function and a test of attention with corpus callosum FA, and a test of executive function with lowered FA in the superior longitudinal fasiculus. These data suggest that demyelination as reflected by the increase in RD may be a prominent disease process in paediatric HIV infection.

CHARGE syndrome: genetic aspects and dental challenges, a review and case presentation.

BACKGROUND: CHARGE syndrome (CS) is a rare genetic condition (OMIM #214800). The condition has a variable phenotypic expression. Historically, the diagnosis of CHARGE syndrome was based on the presence of specific clinical criteria. The genetic aetiology of CS has since been elucidated and attributed to pathogenic variation in the CHD7 gene (OMIM 608892) at chromosome locus 8q12. CASE PRESENTATION: A South African female of mixed ancestry heritage, aged 4 years, was referred for dental assessment to the Faculty of Dentistry, University of the Western Cape, in 2018. She had a diagnosis of CHARGE syndrome confirmed by a Medical Geneticist from the Division of Molecular Biology and Human Genetics at the University of Stellenbosch. The patient had a long prior history of health and developmental problems, with the correct diagnosis becoming apparent over time. She presented with many oral and craniofacial features warranting consideration by the dentist including micrognathia, hypoplastic nasal bones, cranial nerve dysfunction, bruxism, craniofacial anomalies and compromised sensory perception. The treatment was mainly preventive and, although she fed through a percutaneous endoscopic gastrostomy tube (PEG), maintenance of her oral hygiene was necessitated. CONCLUSION: CS is a multisystem condition and the optimal care for an individual is with a specialist multidisciplinary team. The numerous systemic problems affecting these individuals take precedence in their care, and often there is neglect of their dental concerns. Given the abnormalities frequently present in the oral and craniofacial region, the authors recommend that a team of dental and other medical specialists be involved in the management of individuals with CS.

Early-Life Predictors of Fetal Alcohol Spectrum Disorders.

BACKGROUND AND OBJECTIVES: Fetal alcohol spectrum disorders (FASD) comprise the continuum of disabilities associated with prenatal alcohol exposure. Although infancy remains the most effective time for initiation of intervention services, current diagnostic schemes demonstrate the greatest confidence, accuracy, and reliability in school-aged children. Our aims for the current study were to identify growth, dysmorphology, and neurodevelopmental features in infants that were most predictive of FASD at age 5, thereby improving the timeliness of diagnoses. METHODS: A cohort of pregnant South African women attending primary health care clinics or giving birth in provincial hospitals was enrolled in the project. Children were followed longitudinally from birth to 60 months to determine their physical and developmental trajectories (N = 155). Standardized protocols were used to assess growth, dysmorphology, and development at 6 weeks and at 9, 18, 42, and 60 months. A structured maternal interview, including estimation of prenatal alcohol intake, was administered at 42 or 60 months. RESULTS: Growth restriction and total dysmorphology scores differentiated among children with and without FASD as early as 9 months (area under the receiver operating characteristic curve = 0.777; P < .001; 95% confidence interval: 0.705-0.849), although children who were severely affected could be identified earlier. Assessment of developmental milestones revealed significant developmental differences emerging among children with and without FASD between 18 and 42 months. Mothers of children with FASD were significantly smaller, with lower BMIs and higher alcohol intake during pregnancy, than mothers of children without FASD. CONCLUSIONS: Assessment of a combination of growth, dysmorphology, and neurobehavioral characteristics allows for accurate identification of most children with FASD as early as 9 to 18 months.

Replication of High Fetal Alcohol Spectrum Disorders Prevalence Rates, Child Characteristics, and Maternal Risk Factors in a Second Sample of Rural Communities in South Africa.

Background: Prevalence and characteristics of fetal alcohol syndrome (FAS) and total fetal alcohol spectrum disorders (FASD) were studied in a second sample of three South African rural communities to assess change. Methods: Active case ascertainment focused on children with height, weight and/or head circumference ≤25th centile and randomly-selected children. Final diagnoses were based on dysmorphology, neurobehavioral scores, and maternal risk interviews. Results: Cardinal facial features, head circumference, and total dysmorphology scores differentiated specific FASD diagnostic categories in a somewhat linear fashion but all FASD traits were significantly worse than those of randomly-selected controls. Neurodevelopmental delays were significantly worse for children with FASD than controls. Binge alcohol use was clearly documented as the proximal maternal risk factor for FASD, and significant distal risk factors were: low body mass, education, and income; high gravidity, parity, and age at birth of the index child. FAS rates continue to extremely high in these communities at 9-129 per 1000 children. Total FASD affect 196-276 per 1000 or 20-28% of the children in these communities. Conclusions: Very high rates of FASD persist in these general populations where regular, heavy drinking, often in a binge fashion, co-occurs with low socioeconomic conditions.

Who is most affected by prenatal alcohol exposure: Boys or girls?

OBJECTIVE: To examine outcomes among boys and girls that are associated with prenatal alcohol exposure. METHODS: Boys and girls with fetal alcohol spectrum disorders (FASD) and randomly-selected controls were compared on a variety of physical and neurobehavioral traits. RESULTS: Sex ratios indicated that heavy maternal binge drinking may have significantly diminished viability to birth and survival of boys postpartum more than girls by age seven. Case control comparisons of a variety of physical and neurobehavioral traits at age seven indicate that both sexes were affected similarly for a majority of variables. However, alcohol-exposed girls had significantly more dysmorphology overall than boys and performed significantly worse on non-verbal IQ tests than males. A three-step sequential regression analysis, controlling for multiple covariates, further indicated that dysmorphology among girls was significantly more associated with five maternal drinking variables and three distal maternal risk factors. However, the overall model, which included five associated neurobehavioral measures at step three, was not significant (p=0.09, two-tailed test). A separate sequential logistic regression analysis of predictors of a FASD diagnosis, however, indicated significantly more negative outcomes overall for girls than boys (Nagelkerke R2=0.42 for boys and 0.54 for girls, z=-2.9, p=0.004). CONCLUSION: Boys and girls had mostly similar outcomes when prenatal alcohol exposure was linked to poor physical and neurocognitive development. Nevertheless, sex ratios implicate lower viability and survival of males by first grade, and girls have more dysmorphology and neurocognitive impairment than boys resulting in a higher probability of a FASD diagnosis.

The continuum of fetal alcohol spectrum disorders in a community in South Africa: Prevalence and characteristics in a fifth sample.

BACKGROUND: The prevalence and characteristics of the continuum of diagnoses within fetal alcohol spectrum disorders (FASD) were researched in a fifth sample in a South African community. METHODS: An active case ascertainment approach was employed among all first grade learners in this community (n=862). Following individual examination by clinical geneticists/dysmorphologists, cognitive/behavioral testing, and maternal interviews, final diagnoses were made in multidisciplinary case conferences. RESULTS: Physical measurements, cardinal facial features of FAS, and total dysmorphology scores clearly differentiated diagnostic categories in a consistent, linear fashion, from severe to mild. Neurodevelopmental delays and behavioral problems were significantly worse for each of the FASD diagnostic categories, although not as consistently linear across diagnostic groups. Alcohol use was documented by direct report from the mother in 71% to 100% of cases in specific diagnostic groups. Significant distal maternal risk factors in this population are: advanced maternal age at pregnancy; low height, weight, and body mass index (BMI); small head circumference; low education; low income; and rural residence. Even when controlling for socioeconomic status, prenatal drinking correlates significantly with total dysmorphology score, head circumference, and five cognitive and behavioral measures. In this community, FAS occurs in 59-79 per 1,000 children, and total FASD in 170-233 per 1,000 children, or 17% to 23%. CONCLUSIONS: Very high rates of FASD continue in this community where entrenched practices of regular binge drinking co-exist with challenging conditions for childbearing and child development in a significant portion of the population.