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1.
Afr J Lab Med ; 13(1): 2384, 2024.
Article in English | MEDLINE | ID: mdl-38840956

ABSTRACT

Introduction: Maternally inherited diabetes and deafness (MIDD) is caused by the m.3243A>G pathogenic variant in maternally inherited mitochondrial DNA. Diabetes is prevalent in our setting; however, MIDD is rarely diagnosed. This study, undertaken in Pretoria, South Africa, highlights the variable presentation of MIDD in different patients within the same family. Case presentation: A 45-year-old man (proband) with hearing impairment was referred to the endocrine unit in July 2015 due to poor glycaemic control (HbA1c = 13%). His clinical and biochemical features were in keeping with MIDD. A genetic study of accessible maternal relatives was pursued. His mother had difficulty hearing and reportedly died from an unspecified cardiovascular cause. Two sisters with diabetes and deafness died of cardiac-related conditions. One nephew had diabetes (HbA1c = 7.7%), hearing loss and tested positive for m.3243A>G. A third sister tested positive for m3243A>G, but aside from bilateral mild hearing loss in higher frequencies, showed no other signs of target organ damage. Her daughter developed end-stage kidney failure necessitating a transplant, while her son had no biochemical abnormalities and was negative for m.3243A>G. Management and outcome: A multidisciplinary team managed and screened for complications of the patient and his maternal relatives. Proband died prior to genetic testing. Conclusion: Most MIDD patients initially present with symptoms of diabetes only, and it is probable that many cases remain undiagnosed. A high index of suspicion is necessary when encountering a family history of both diabetes and impaired hearing, and screening should be offered to the patient's maternal relatives. What the study adds: This study demonstrates the importance of proper assessment when evaluating a patient with diabetes and a family history of hearing loss.

2.
Eur J Hum Genet ; 32(7): 813-818, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38605124

ABSTRACT

Persistent congenital hyperinsulinism (HI) is a rare genetically heterogeneous condition characterised by dysregulated insulin secretion leading to life-threatening hypoglycaemia. For up to 50% of affected individuals screening of the known HI genes does not identify a disease-causing variant. Large deletions have previously been used to identify novel regulatory regions causing HI. Here, we used genome sequencing to search for novel large (>1 Mb) deletions in 180 probands with HI of unknown cause and replicated our findings in a large cohort of 883 genetically unsolved individuals with HI using off-target copy number variant calling from targeted gene panels. We identified overlapping heterozygous deletions in five individuals (range 3-8 Mb) spanning chromosome 20p11.2. The pancreatic beta-cell transcription factor gene, FOXA2, a known cause of HI was deleted in two of the five individuals. In the remaining three, we found a minimal deleted region of 2.4 Mb adjacent to FOXA2 that encompasses multiple non-coding regulatory elements that are in conformational contact with FOXA2. Our data suggests that the deletions in these three children may cause disease through the dysregulation of FOXA2 expression. These findings provide new insights into the regulation of FOXA2 in the beta-cell and confirm an aetiological role for chromosome 20p11.2 deletions in syndromic HI.


Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 20 , Congenital Hyperinsulinism , Hepatocyte Nuclear Factor 3-beta , Humans , Hepatocyte Nuclear Factor 3-beta/genetics , Hepatocyte Nuclear Factor 3-beta/metabolism , Congenital Hyperinsulinism/genetics , Congenital Hyperinsulinism/pathology , Chromosomes, Human, Pair 20/genetics , Female , Male , Regulatory Sequences, Nucleic Acid
3.
Front Genet ; 15: 1331278, 2024.
Article in English | MEDLINE | ID: mdl-38596211

ABSTRACT

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic condition with complete age-dependent penetrance, variable expressivity and a global prevalence of ∼1/3,000. It is characteriszed by numerous café-au-lait macules, skin freckling in the inguinal or axillary regions, Lisch nodules of the iris, optic gliomas, neurofibromas, and tumour predisposition. The diagnostic testing strategy for NF1 includes testing for DNA single nucleotide variants (SNVs), copy number variants (CNVs) as well as RNA analysis for deep intronic and splice variants, which can cumulatively identify the causative variant in 95% of patients. In the present study, NF1 patients were screened using a next-generation sequencing (NGS) assay targeting NF1 exons and intron/exon boundaries for SNV and NF1 multiple ligation-dependent probe amplification (MLPA) analysis for CNV detection. Twenty-six unrelated Southern African patients clinically suspected of having NF1, based on the clinical diagnostic criteria developed by the National Institute of Health (NIH), were included in the current study. A detection rate of 58% (15/26) was obtained, with SNVs identified in 80% (12/15) using a targeted gene panel and NF1 gene deletion in 20% (3/15) identified using MLPA. Ten patients (38%) had no variants identified, although they met NF1 diagnostic criteria. One VUS was identified in this study in a patient that met NF1 diagnostic criteria, however there was no sufficient information to classify variant as pathogenic. The clinical features of Southern African patients with NF1 are similar to that of the known NF1 phenotype, with the exception of a lower frequency of plexiform neurofibromas and a higher frequency of developmental/intellectual disability compared to other cohorts. This is the first clinical and molecular characterisation of a Southern African ancestry NF1 cohort using both next-generation sequencing and MLPA analysis. A significant number of patients remained without a diagnosis following DNA-level testing. The current study offers a potential molecular testing strategy for our low resource environment that could benefit a significant proportion of patients who previously only received a clinical diagnosis without molecular confirmation.

4.
Mol Genet Genomic Med ; 12(1): e2342, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38284454

ABSTRACT

BACKGROUND: Cornelia de Lange Syndrome (CdLS) presents with a variable multi-systemic phenotype and pathogenic variants have been identified in five main genes. This condition has been understudied in African populations with little phenotypic and molecular information available. METHODS AND RESULTS: We present a cohort of 14 patients with clinical features suggestive of CdLS. Clinical phenotyping was carried out and cases were classified according to the international consensus criteria. According to this criteria, nine patients had classical CdLS, one had non-classical CdLS and four presented with a phenotype that suggested molecular testing for CdLS. Each patient underwent mutation profiling using a targeted next generation sequencing panel of 18 genes comprising known and suspected CdLS causal genes. Of the 14 patients tested, pathogenic and likely pathogenic variants were identified in nine: eight variants in the NIPBL gene and one in the STAG1 gene. CONCLUSIONS: We present the first molecular data for a cohort of South African patients with CdLS. Eight of the nine variants identified were in the NIPBL gene, the most commonly involved gene in cases of CdLS. This is also the first report of a patient of African ancestry presenting with STAG1-related CdLS.


Subject(s)
Cell Cycle Proteins , De Lange Syndrome , Humans , Cell Cycle Proteins/genetics , De Lange Syndrome/genetics , De Lange Syndrome/pathology , South Africa , Mutation , Phenotype
5.
J Community Genet ; 15(1): 39-48, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37815686

ABSTRACT

Timely and accurate diagnosis of rare genetic disorders is critical, as it enables improved patient management and prognosis. In a resource-constrained environment such as the South African State healthcare system, the challenge is to design appropriate and cost-effective assays that will enable accurate genetic diagnostic services in patients of African ancestry across a broad disease spectrum. Next-generation sequencing (NGS) has transformed testing approaches for many Mendelian disorders, but this technology is still relatively new in our setting and requires cost-effective ways to implement. As a proof of concept, we describe a feasible diagnostic strategy for genetic disorders frequently seen in our genetics clinics (RASopathies, Cornelia de Lange syndrome, Treacher Collins syndrome, and CHARGE syndrome). The custom-designed targeted NGS gene panel enabled concurrent variant screening for these disorders. Samples were batched during sequencing and analyzed selectively based on the clinical phenotype. The strategy employed in the current study was cost-effective, with sequencing and analysis done at USD849.68 per sample and achieving an overall detection rate of 54.5%. The strategy employed is cost-effective as it allows batching of samples from patients with different diseases in a single run, an approach that can be utilized with rare and less frequently ordered molecular diagnostic tests. The subsequent selective analysis pipeline allowed for timeous reporting back of patients results. This is feasible with a reasonable yield and can be employed for the molecular diagnosis of a wide range of rare monogenic disorders in a resource-constrained environment.

6.
J Community Genet ; 13(6): 641-654, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36214965

ABSTRACT

Computer-aided facial diagnostic tools are valuable emerging technologies for the early detection and initial diagnosis of congenital disorders. These tools require large datasets of facial photographs, especially of infants and children, to identify these disorders and improve classification accuracies. Researchers need to balance this need for larger datasets with patients' privacy rights, needs and preferences. This study aimed to investigate parents' views regarding the collection, storage, use and publication of their children's facial images for research and diagnostic purposes. A total of 151 parents of children with and without congenital disorders completed an online survey evaluating their views on the collection, storage, use and publication of children's facial images for research and diagnosis. Overall, 72.5% of parents would allow researchers to take facial photographs of their children, preferring the images to be stored in a secure database that is not available to the public. Parents of children with congenital disorders were more accepting of researchers taking facial photographs of their children, compared to parents of children without these conditions. Half of the respondents would allow facial photographs of their children to be published in academic journals, without their eyes covered, and this acceptance increased as the proportion of the child's face covered increased. Parents also indicated specific requirements to allow the use of these images in other similar research studies which need to be taken into consideration when planning studies that involve facial analysis research.

8.
BMC Med Genomics ; 13(1): 34, 2020 03 06.
Article in English | MEDLINE | ID: mdl-32143628

ABSTRACT

BACKGROUND: Application of whole genome sequencing (WGS) enables identification of non-coding variants that play a phenotype-modifying role and are undetectable by exome sequencing. Recently, non-coding regulatory single nucleotide variants (SNVs) have been reported in patients with lethal lung developmental disorders (LLDDs) or congenital scoliosis with recurrent copy-number variant (CNV) deletions at 17q23.1q23.2 or 16p11.2, respectively. CASE PRESENTATION: Here, we report a deceased newborn with pulmonary hypertension and pulmonary interstitial emphysema with features suggestive of pulmonary hypoplasia, resulting in respiratory failure and neonatal death soon after birth. Using the array comparative genomic hybridization and WGS, two heterozygous recurrent CNV deletions: ~ 2.2 Mb on 17q23.1q23.2, involving TBX4, and ~ 600 kb on 16p11.2, involving TBX6, that both arose de novo on maternal chromosomes were identified. In the predicted lung-specific enhancer upstream to TBX4, we have detected seven novel putative regulatory non-coding SNVs that were absent in 13 control individuals with the overlapping deletions but without any structural lung anomalies. CONCLUSIONS: Our findings further support a recently reported model of complex compound inheritance of LLDD in which both non-coding and coding heterozygous TBX4 variants contribute to the lung phenotype. In addition, this is the first report of a patient with combined de novo heterozygous recurrent 17q23.1q23.2 and 16p11.2 CNV deletions.


Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 17/genetics , Exome Sequencing , Hypertension, Pulmonary/genetics , Polymorphism, Single Nucleotide , Fatal Outcome , Female , Humans , Hypertension, Pulmonary/pathology , Infant, Newborn , Lung/pathology
9.
Ann Maxillofac Surg ; 9(1): 140-145, 2019.
Article in English | MEDLINE | ID: mdl-31293943

ABSTRACT

CONTEXT: Cleft patients with Holoprosencephaly (HPE) constitute a controversy due to a variable facial appearance. HPE appearance varies from only a columella to a prolabium-premaxilla complex agenesis up to a common unilateral or bilateral cleft lip and palate with a single central incisor, various brain deformities, and/or even normal brain development. It is challenging to designate such various appearances, to understand their etiopathogenesis, and to choose the most appropriate management. Literature was reviewed for diagnostic criteria, pregnancy history, clinical findings, brain development, survival rate, initial perioperative management, and postsurgical midfacial growth in cleft patients with HPE. The findings were compared with a clinical database of 85 cleft patients with HPE at the Department of Maxillofacial and Oral Surgery, University of Pretoria. AIMS OF PART 1: The aim of the study is to overcome disparities widely existing among clinicians regarding definitive diagnostic criteria, especially in cases with a common appearance of a uni- or bilateral cleft lip alveolus or cleft lip, alveolus and palate deformity, and cases presenting facial structural agenesis. MATERIALS AND METHODS: A literature search related to diagnostic criteria was compared to results of a cleft HPE database from a single tertiary institution. RESULTS: HPE cleft cases can be allocated to one of the following subdivisions: (1) columella complex agenesis (Ag-Colum), (2) prolabium-premaxilla-columella complex agenesis in cleft lip-alveolus deformities (Ag-CLA), (3) prolabium-premaxilla-columella agenesis in cases with complete cleft lip alveolus palate (Ag-CLAP), and (4) standard type (holoprosencephaly in patients with a standard cleft) with uni- or bilateral CLA or CLAP, hard and soft palate cleft (hPsP), and atrophic premaxillae, with or without single central incisor. Further, incidence, variation in brain development, and appearances in HPE cleft patients of different races and gender, epilepsy, and early death are discussed. Conclusion: This paper adds new data and facts to the existing literature related to cleft lip and palate patients suffering from HPE.

10.
Am J Med Genet A ; 179(2): 150-158, 2019 02.
Article in English | MEDLINE | ID: mdl-30614194

ABSTRACT

Cornelia de Lange syndrome (CdLS) is a dominant multisystemic malformation syndrome due to mutations in five genes-NIPBL, SMC1A, HDAC8, SMC3, and RAD21. The characteristic facial dysmorphisms include microcephaly, arched eyebrows, synophrys, short nose with depressed bridge and anteverted nares, long philtrum, thin lips, micrognathia, and hypertrichosis. Most affected individuals have intellectual disability, growth deficiency, and upper limb anomalies. This study looked at individuals from diverse populations with both clinical and molecularly confirmed diagnoses of CdLS by facial analysis technology. Clinical data and images from 246 individuals with CdLS were obtained from 15 countries. This cohort included 49% female patients and ages ranged from infancy to 37 years. Individuals were grouped into ancestry categories of African descent, Asian, Latin American, Middle Eastern, and Caucasian. Across these populations, 14 features showed a statistically significant difference. The most common facial features found in all ancestry groups included synophrys, short nose with anteverted nares, and a long philtrum with thin vermillion of the upper lip. Using facial analysis technology we compared 246 individuals with CdLS to 246 gender/age matched controls and found that sensitivity was equal or greater than 95% for all groups. Specificity was equal or greater than 91%. In conclusion, we present consistent clinical findings from global populations with CdLS while demonstrating how facial analysis technology can be a tool to support accurate diagnoses in the clinical setting. This work, along with prior studies in this arena, will assist in earlier detection, recognition, and treatment of CdLS worldwide.


Subject(s)
Abnormalities, Multiple/genetics , Cell Cycle Proteins/genetics , De Lange Syndrome/genetics , Intellectual Disability/genetics , Abnormalities, Multiple/epidemiology , Abnormalities, Multiple/physiopathology , Adolescent , Adult , Child , Child, Preschool , Chondroitin Sulfate Proteoglycans/genetics , Chromosomal Proteins, Non-Histone/genetics , De Lange Syndrome/epidemiology , De Lange Syndrome/physiopathology , Face/physiopathology , Female , Humans , Image Processing, Computer-Assisted , Infant , Infant, Newborn , Intellectual Disability/epidemiology , Intellectual Disability/physiopathology , Male , Mutation , Phenotype , Racial Groups/genetics , Young Adult
11.
Appl Clin Genet ; 11: 111-120, 2018.
Article in English | MEDLINE | ID: mdl-30498368

ABSTRACT

Pena-Shokeir syndrome (PSS) type 1, also known as fetal akinesia deformation sequence, is a rare genetic syndrome that almost always results in intrauterine or early neonatal death. It is characterized by markedly decreased fetal movements, intrauterine growth restriction, joint contractures, short umbilical cord, and features of pulmonary hypoplasia. Antenatal diagnosis can be difficult. Ultrasound features are varied and may overlap with those of Trisomy 18. The poor prognosis of PSS is due to pulmonary hypoplasia, which is an important feature that distinguishes PSS from arthrogryposis multiplex congenital without pulmonary hypoplasia, which has a better prognosis. If diagnosed in the antenatal period, a late termination of pregnancy can be considered following ethical discussion (if the law allows). In most cases, a diagnosis is only made in the neonatal period. Parents of a baby affected with PSS require detailed counseling that includes information on the imprecise recurrence risks and a plan for subsequent pregnancies.

12.
Am J Med Genet A ; 176(5): 1128-1136, 2018 05.
Article in English | MEDLINE | ID: mdl-29681090

ABSTRACT

Williams-Beuren syndrome (WBS) is a common microdeletion syndrome characterized by a 1.5Mb deletion in 7q11.23. The phenotype of WBS has been well described in populations of European descent with not as much attention given to other ethnicities. In this study, individuals with WBS from diverse populations were assessed clinically and by facial analysis technology. Clinical data and images from 137 individuals with WBS were found in 19 countries with an average age of 11 years and female gender of 45%. The most common clinical phenotype elements were periorbital fullness and intellectual disability which were present in greater than 90% of our cohort. Additionally, 75% or greater of all individuals with WBS had malar flattening, long philtrum, wide mouth, and small jaw. Using facial analysis technology, we compared 286 Asian, African, Caucasian, and Latin American individuals with WBS with 286 gender and age matched controls and found that the accuracy to discriminate between WBS and controls was 0.90 when the entire cohort was evaluated concurrently. The test accuracy of the facial recognition technology increased significantly when the cohort was analyzed by specific ethnic population (P-value < 0.001 for all comparisons), with accuracies for Caucasian, African, Asian, and Latin American groups of 0.92, 0.96, 0.92, and 0.93, respectively. In summary, we present consistent clinical findings from global populations with WBS and demonstrate how facial analysis technology can support clinicians in making accurate WBS diagnoses.


Subject(s)
Biological Variation, Population , Genetic Heterogeneity , Williams Syndrome/diagnosis , Williams Syndrome/genetics , Anthropometry/methods , Facies , Humans , Phenotype , Population Groups , Reproducibility of Results , Sensitivity and Specificity , Williams Syndrome/epidemiology
13.
J Neurol Sci ; 384: 121-125, 2018 Jan 15.
Article in English | MEDLINE | ID: mdl-29249369

ABSTRACT

Neonatal-onset multiple acyl-CoA dehydrogenase deficiency (MADD type I) is an autosomal recessive disorder of the electron transfer flavoprotein function characterized by a severe clinical and biochemical phenotype, including congenital abnormalities with unresponsiveness to riboflavin treatment as distinguishing features. From a retrospective study, relying mainly on metabolic data, we have identified a novel mutation, c.1067G>A (p.Gly356Glu) in exon 8 of ETFDH, in three South African Caucasian MADD patients with the index patient presenting the hallmark features of type I MADD and two patients with compound heterozygous (c.1067G>A+c.1448C>T) mutations presenting with MADD type III. SDS-PAGE western blot confirmed the significant effect of this mutation on ETFDH structural instability. The identification of this novel mutation in three families originating from the South African Afrikaner population is significant to direct screening and strategies for this disease, which amongst the organic acidemias routinely screened for, is relatively frequently observed in this population group.


Subject(s)
Electron-Transferring Flavoproteins/genetics , Iron-Sulfur Proteins/genetics , Multiple Acyl Coenzyme A Dehydrogenase Deficiency/genetics , Mutation , Oxidoreductases Acting on CH-NH Group Donors/genetics , Child , Family , Fatal Outcome , Female , Humans , Infant, Newborn , Male , Multiple Acyl Coenzyme A Dehydrogenase Deficiency/physiopathology , Phenotype , Retrospective Studies , South Africa , White People/genetics , Young Adult
14.
Am J Med Genet A ; 173(9): 2323-2334, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28748642

ABSTRACT

Noonan syndrome (NS) is a common genetic syndrome associated with gain of function variants in genes in the Ras/MAPK pathway. The phenotype of NS has been well characterized in populations of European descent with less attention given to other groups. In this study, individuals from diverse populations with NS were evaluated clinically and by facial analysis technology. Clinical data and images from 125 individuals with NS were obtained from 20 countries with an average age of 8 years and female composition of 46%. Individuals were grouped into categories of African descent (African), Asian, Latin American, and additional/other. Across these different population groups, NS was phenotypically similar with only 2 of 21 clinical elements showing a statistically significant difference. The most common clinical characteristics found in all population groups included widely spaced eyes and low-set ears in 80% or greater of participants, short stature in more than 70%, and pulmonary stenosis in roughly half of study individuals. Using facial analysis technology, we compared 161 Caucasian, African, Asian, and Latin American individuals with NS with 161 gender and age matched controls and found that sensitivity was equal to or greater than 94% for all groups, and specificity was equal to or greater than 90%. In summary, we present consistent clinical findings from global populations with NS and additionally demonstrate how facial analysis technology can support clinicians in making accurate NS diagnoses. This work will assist in earlier detection and in increasing recognition of NS throughout the world.


Subject(s)
Face/physiopathology , Genetics, Population , Noonan Syndrome/genetics , Asian People , Black People/genetics , Child , Female , Humans , Male , Mitogen-Activated Protein Kinase Kinases/genetics , Noonan Syndrome/physiopathology , Signal Transduction , White People/genetics , ras Proteins/genetics
15.
S Afr Med J ; 107(5): 457-462, 2017 Apr 25.
Article in English | MEDLINE | ID: mdl-28492130

ABSTRACT

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.

16.
Fam Cancer ; 16(3): 441-446, 2017 07.
Article in English | MEDLINE | ID: mdl-28185119

ABSTRACT

Fanconi anaemia (FA) is a genotypically and phenotypically heterogeneous genetic condition, characterized cytogenetically by chromosomal instability and breakage secondary to impaired DNA repair mechanisms. Affected individuals typically manifest growth restriction and congenital physical abnormalities and most progress to hematological disease including bone marrow aplasia. A rare genetic subtype of FA (FA-D1) is caused by biallelic mutations in the BRCA2 gene. Affected individuals manifest severe congenital anomalies and significant pigmentary changes and are additionally at risk for early onset leukemia and certain solid organ malignancies, including Wilms tumors and brain tumors. Parents of affected individuals are obligate carriers for heterozygous BRCA2 mutations and are thus potentially at risk for adult onset cancers which fall within the hereditary breast and ovarian cancer spectrum. We present two cases of black South African patients with FA diagnosed with biallelic BRCA2 mutations and discuss the phenotypic consequences and implications for them and their families. Recognition of this severe end of the phenotypic spectrum of FA is critical in allowing for confirmation of the diagnosis as well as cascade screening and appropriate care of family members.


Subject(s)
BRCA2 Protein/genetics , Fanconi Anemia/genetics , Genetic Predisposition to Disease/genetics , Child, Preschool , Female , Genes, BRCA2 , Humans , Infant , Infant, Newborn , Male , Mutation , Pedigree , South Africa
17.
J Pediatr Surg ; 51(2): 268-71, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26852091

ABSTRACT

BACKGROUND: Mowat Wilson syndrome (MWS) is an uncommon association of Hirschsprung's disease (HSCR). Phenotypic features may develop with time, causing initial difficulties in diagnosis. MWS results from haploinsufficiency of the Zinc finger E-box-binding homeobox 2 (ZEB2) gene, and molecular diagnosis of ZEB2 mutation is required to confirm the diagnosis. We report the first confirmed cases of MWS in three children with the typical facial features, mental retardation, absent corpus callosum, epilepsy, and HSCR and novel Zeb2 variations on DNA analysis. METHODOLOGY: Clinical features were monitored. DNA extracted from peripheral blood was subjected to bidirectional sequencing analysis following PCR DNA amplification. ZEB2 gene results were compared to the ZEB2 reference sequence (ENS00000169554) for variation. Bioinformatic investigation of novel gene variants was via the "Blastx" program function available via the National Center for Biotechnology Information (http://www.bioinfo.org/NPInter/blast/blast_link.cgi). RESULTS: Clinical follow-up showed that the phenotypic features were not all present at birth but developed with time in 2 surviving patients. Several Zeb2 variations were detected in the promoter region of the ZEB2 gene of which 2 were novel (-56A/T 1174 11A/12A). In addition, a novel heterozygous single nucleotide insertion in exon 2 of ZEB2 in one patient results in a frameshift causing deletion of the first 8 amino acids of the ZEB2 protein and an alteration of amino acids 9 (G9A), 11 (R11G), and 12 (C12A). In the third patient, a novel single nucleotide deletion exon 8 (1784delC Het) results in a frameshift at amino acid 595 of translated protein. This shortens protein from 1214 to 594 amino acids and affects the functionality of the critical ZEB2 protein. CONCLUSIONS: MWS is an important link to recognise clinically. It underlines the functionality of the Zeb2 gene in certain syndromic Hirschsprung's disease. These variations probably contribute to the clinical features of the Mowat Wilson phenotype in Hirschsprung's disease but should be confirmed in further research.


Subject(s)
Hirschsprung Disease/genetics , Homeodomain Proteins/genetics , Intellectual Disability/genetics , Microcephaly/genetics , Mutation , Repressor Proteins/genetics , Child , Child, Preschool , Facies , Female , Genetic Markers , Hirschsprung Disease/diagnosis , Humans , Infant , Infant, Newborn , Intellectual Disability/diagnosis , Male , Microcephaly/diagnosis , Phenotype , Zinc Finger E-box Binding Homeobox 2
18.
S Afr Med J ; 105(7): 540-3, 2015 Sep 21.
Article in English | MEDLINE | ID: mdl-26428746

ABSTRACT

Autosomal dominantly inherited oculopharyngeal muscular dystrophy (OPMD) is caused by a trinucleotide repeat expansion in exon 1 of the polyadenylate binding protein nuclear 1 (PABPN1) gene on chromosome 14q. A large family with OPMD was recently identified in Pretoria, South Africa (SA). Molecular studies revealed a (GCG)11(GCA)3GCG or (GCN)15 mutant allele. The (GCN)15 mutation detected in this family has been described previously in families from Uruguay and Mexico as a founder effect. To our knowledge, this is the first report of an SA Afrikaner family with molecularly confirmed OPMD. The proband, a 64-year-old woman, presented to the neurology outpatient department at Steve Biko Academic Hospital, Pretoria. A sibship of 18 individuals was identified, of whom eight had OPMD. Four patients were interviewed and examined clinically, and electromyographic studies were performed. Molecular analysis of the PABPN1 gene was performed by polymerase chain reaction amplification and direct sequencing of exon 1 in three of the patients. Patients presented with ptosis, external ophthalmoplegia, dysphagia, dysarthria and mild proximal weakness. High foot arches and absent ankle reflexes raised the possibility of peripheral neuropathy, but electromyography showed only mildly low sensory amplitudes, and myopathic units in two patients.

20.
AIDS ; 28(15): 2259-68, 2014 Sep 24.
Article in English | MEDLINE | ID: mdl-25115319

ABSTRACT

OBJECTIVE: To evaluate the safety of combination antiretroviral therapy (ART) in conception and pregnancy in different health systems. DESIGN: A pilot ART registry to measure the prevalence of birth defects and adverse pregnancy outcomes in South Africa and Zambia. METHODS: HIV-infected pregnant women on ART prior to conception were enrolled until delivery, and their infants were followed until 1 year old. RESULTS: Between October 2010 and April 2011, 600 women were enrolled. The median CD4 cell count at study enrollment was lower in South Africa than Zambia (320 vs. 430 cells/µl; P < 0.01). The most common antiretroviral drugs at the time of conception included stavudine, lamivudine, and nevirapine. There were 16 abortions (2.7%), one ectopic pregnancy (0.2%), 12 (2.0%) stillbirths, and 571 (95.2%) live infants. Deliveries were more often preterm (29.7 vs. 18.4%; P = 0.01) and the infants had lower birth weights (2900 vs. 2995 g; P = 0.11) in Zambia compared to South Africa. Thirty-six infants had birth defects: 13 major and 23 minor. There were more major anomalies detected in South Africa and more minor ones in Zambia. No neonatal deaths were attributed to congenital birth defects. CONCLUSIONS: An Africa-specific, multi-site antiretroviral drug safety registry for pregnant women is feasible. Different prevalence for preterm delivery, delivery mode, and birth defect types between women on preconception ART in South Africa and Zambia highlight the potential impact of health systems on pregnancy outcomes. As countries establish ART drug safety registries, documenting health facility limitations may be as essential as the specific ART details.


Subject(s)
Anti-Retroviral Agents/adverse effects , Antiretroviral Therapy, Highly Active/adverse effects , Congenital Abnormalities/epidemiology , HIV Infections/drug therapy , Pregnancy Complications, Infectious/drug therapy , Pregnancy Outcome , Premature Birth/epidemiology , Adolescent , Adult , Anti-Retroviral Agents/administration & dosage , Antiretroviral Therapy, Highly Active/methods , Female , Humans , Infant , Infant, Newborn , Middle Aged , Pregnancy , Prevalence , South Africa/epidemiology , Young Adult , Zambia/epidemiology
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