The incidence of Down's syndrome in Nigeria

Correlates of knowledge of genetic diseases and congenital anomalies among pregnant women attending antenatal clinics in Lagos, South-West Nigeria

Introduction

genetic diseases and congenital anomalies place a significant burden on the health of new-borns and their mothers. Despite the availability of a variety of prenatal screening tests, mothers' knowledge has been documented to determine uptake. This study aims to assess the knowledge of pregnant women about birth defects and the associated correlates with regard to willingness to do prenatal screening.

Methods

a cross-sectional descriptive study was conducted among 422 antenatal mothers recruited sequentially as they attended antenatal clinics at the Lagos University Teaching Hospital. An interviewer-administered questionnaire was used to determine their knowledge of birth defects and willingness to do prenatal testing.

Results

majority of the participants (92.2%) had at least secondary education. The mean total knowledge score of the respondents was 63%. Age and knowledge scores were not significantly correlated (r=-0.071, p=0.14). Being employed predicted higher knowledge scores (95% CI: 0.09, 2.09, p=0.03). Respondents who had primary school education and those who replied “I don't know” to willingness to test had significantly lower knowledge scores (95% CI: -15.01, -1.19, p=0.02 and 95% CI: -4.52, -0.68, p=0.01 respectively). Majority (79.1%) of the respondents were willing to undergo testing. Respondents' level of education was significantly associated with willingness to test (p=0.03).

Conclusion

the observed knowledge gaps were considerable. There is need for improvement in education, the empowerment of women and access to quality healthcare including prenatal screening.

Diversity and dysmorphology

PURPOSE OF REVIEW

Dysmorphic features result from errors in morphogenesis frequently associated with genetic syndromes. Recognizing patterns of dysmorphic features is a critical step in the diagnosis and management of human congenital anomalies and genetic syndromes. This review presents recent developments in genetic syndromes and their related dysmorphology in diverse populations.

RECENT FINDINGS

Clinical findings in patients with genetic syndromes differ in their heterogeneity across different population groups. Some genetic syndromes have variable features in different ethnicities, in part due to specific background exam characteristics such as flat facial profiles or nasal differences; however, other genetic syndromes are similar across different ethnicities. Facial analysis technology is accurate in diagnosing genetic syndromes in populations around the world and is a powerful adjunct to conventional clinical examination. This accuracy also reinforces the concept that genetic syndromes can and should be diagnosed in any ethnicity.

SUMMARY

The increasing amount of data from studies on genetic syndromes in diverse populations is significantly improving our knowledge and approach to dysmorphic patients from various ethnic backgrounds. Optimal management of genetic syndromes requires early diagnosis, including in developing countries.

Prospects of genetic testing for steroid-resistant nephrotic syndrome in Nigerian children: a narrative review of challenges and opportunities

The prevalence of childhood steroid-resistant nephrotic syndrome (SRNS) ranges from 35% to 92%. This steroid resistance among Nigerian children also reflects underlying renal histopathology, revealing a rare minimal-change disease and a varying burden of membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis (FSGS). FSGS tends to progress to end-stage kidney disease, which requires dialysis and/or renal transplantation. While knowledge of the molecular basis of NS is evolving, recent data support the role of mutant genes that otherwise maintain the structural and functional composition of the glomerular filtration barrier to account for many monogenic forms of FSGS. With the advent of next-generation sequencing, >39 genes are currently associated with SRNS, and the number is likely to increase in the near future. Monogenic FSGS is primarily resistant to steroids, and this foreknowledge obviates the need for steroids, other immunosuppressive therapy, and renal biopsy. Therefore, a multidisciplinary collaboration among cell biologists, molecular physiologists, geneticists, and clinicians holds prospects of fine-tuning the management of SRNS caused by known mutant genes. This article describes the genetics of NS/SRNS in childhood and also gives a narrative review of the challenges and opportunities for molecular testing among children with SRNS in Nigeria. For these children to benefit from genetic diagnosis, Nigeria must aspire to have and develop the manpower and infrastructure required for medical genetics and genomic medicine, leveraging on her existing experiences in genomic medicine. Concerted efforts can be put in place to increase the number of enrollees in Nigeria’s National Health Insurance Scheme (NHIS). The scope of the NHIS can be expanded to cater for the expensive bill of genetic testing within or outside the structure of the National Renal Care Policy proposed by Nigerian nephrologists.

Parental views on plastic surgery for Down syndrome: an African perspective

Introduction

Plastic surgery for Down syndrome has not been embraced in sub-Saharan Africa. This study sought to determine the attitudes of some parents from sub-Saharan Africa to plastic surgery for their Down syndrome child.

Methods

Consenting parents completed a questionnaire survey instrument that obtained demographic characteristics and contained a likert scale on attitudes to plastic surgery. Internal consistency of the scale was determined with Chronbach's alpha and Pearsons chi square analysis was used to analyze relationships between demographic variables and attitudes scores. Values less than 0.05 were considered statistically significant.

Results

Most (61.9%) of the 42 consenting mothers were above 35 years of age. The most disturbing of the Down syndrome characteristics were the protruding tongue, 18(42.9%), slanting palpebral fissures, 14(33.3%) and the flattened nasal bridge 14(33.3%). Although the mothers had low awareness of plastic surgery most of them had favourable attitudes towards it. A reliability analysis of the mother's attitudes on the likert scale showed good internal consistency. Chronbachs alpha 0.87.

Conclusion

The parents in this study have favourable attitudes towards plastic surgery for Down syndrome. The prominent tongue was the most disturbing feature.

Medical genetics and genomic medicine in Nigeria

Medical genetics and genomic medicine in Nigeria.

Down syndrome in diverse populations

Down syndrome is the most common cause of cognitive impairment and presents clinically with universally recognizable signs and symptoms. In this study, we focus on exam findings and digital facial analysis technology in individuals with Down syndrome in diverse populations. Photos and clinical information were collected on 65 individuals from 13 countries, 56.9% were male and the average age was 6.6 years (range 1 month to 26 years; SD = 6.6 years). Subjective findings showed that clinical features were different across ethnicities (Africans, Asians, and Latin Americans), including brachycephaly, ear anomalies, clinodactyly, sandal gap, and abundant neck skin, which were all significantly less frequent in Africans (P < 0.001, P < 0.001, P < 0.001, P < 0.05, and P < 0.05, respectively). Evaluation using a digital facial analysis technology of a larger diverse cohort of newborns to adults (n = 129 cases; n = 132 controls) was able to diagnose Down syndrome with a sensitivity of 0.961, specificity of 0.924, and accuracy of 0.943. Only the angles at medial canthus and ala of the nose were common significant findings amongst different ethnicities (Caucasians, Africans, and Asians) when compared to ethnically matched controls. The Asian group had the least number of significant digital facial biometrics at 4, compared to Caucasians at 8 and Africans at 7. In conclusion, this study displays the wide variety of findings across different geographic populations in Down syndrome and demonstrates the accuracy and promise of digital facial analysis technology in the diagnosis of Down syndrome internationally. © 2016 Wiley Periodicals, Inc.

Down syndrome: An overview

Optometrists as primary eye care providers examine patients from diverse populations, including those with special needs such as Down syndrome. Down syndrome is a chromosomal abnormality associated with several health conditions including vision anomalies such as refractive, accommodative and vergence anomalies, as well as ocular pathology. In this article, a narrative review of Down syndrome including the background, historical perspective, aetiology and genetic mechanisms, types, epidemiology, as well as the physical and medical profile of Down syndrome is presented.Keywords: Down syndrome review; Trisomy 21; historical perspective; etiology; types and epidemiology; features; Optometrist

The Incidence of Cardiac Lesions among Children with Down's Syndrome in Jamaica - A Prospective Study

OBJECTIVES

This study aimed to define the incidence of Down's syndrome and to describe the epidemiology of cardiac lesions in Jamaican children with Down's syndrome.

METHODS

A prospective study was conducted on 53 infants during the period January 1, 2007 to December 31, 2007, at the Bustamante Hospital for Children, Kingston, Jamaica. A medical history, physical examination and echo Doppler was performed on each child.

RESULTS

Forty-six thousand babies were born in Jamaica in 2007, of which 53 infants were diagnosed with Down's syndrome, giving an incidence of 1:868. Forty-two (79.2%) infants had congenital heart lesions. Of the 42 patients with cardiac lesions, 50% had an isolated cardiac lesion while 50% had multiple defects. The most common single defect was the atrioventricular septal defect found in 10 (24%) patients. The most frequent concomitant malformation was a patent ductus arteriosus, found in 16 (38.1%) of the patients. The median age of diagnosis with Down's syndrome was 0.14 weeks (interquartile range (IQR) 0 to 68 weeks). The median age of diagnosis with the cardiac lesion was 15.1 weeks (IQR 0 to 40.0 weeks).

CONCLUSIONS

The incidence of Down's syndrome in Jamaica is similar to the reported international experience. The distribution of cardiac malformations is similar to other countries; however, the main difference is the higher incidence of congenital heart disease and a higher incidence of combined lesions.

Dysmorphism in One of a Set of Male Twins; Could They have been Identical Twins? A Diagnostic Dilemma

Twinning occurs worldwide, but Nigerian women of the southwest extraction record one of the highest rates in the world. Among the notable risk factors for fraternal twinning is advanced maternal age, which is also an independent risk factor for Down syndrome. Even as morphological characteristics can easily be applied to distinguish identical from fraternal twins, in cases of an associated dysmorphism, in any member of the couplet, it becomes a difficult tool to use, as has been observed in the case of a set of twins who were of the same sex, blood group, hemoglobin genotype, and shared the same placenta.

Benefits and challenges of newborn hearing screening for developing countries

The late detection of permanent congenital and early-onset hearing loss (PCEHL) often has severe effects on linguistic, speech, cognitive and educational development in affected children. Since newborn hearing screening (NHS) allows most PCEHL to be detected early enough for optimal intervention, the prospects of its introduction in the developing world are reviewed in this paper. It is observed that a simple generalisation on the feasibility of NHS for the developing countries seems inappropriate in view of the diversities in the health and socio-economic status of these countries and the recent favourable reports of universal newborn hearing screening from the region. NHS empowers parents to make timely choices that will allow their hearing impaired children to be given a good start in life and be fully integrated into the wider community. It also compels attention towards the development of essential hearing healthcare services, besides the specific documented benefits. Existing child-healthcare structures such as the expanded programme on immunisation (EPI), baby friendly hospital initiatives (BFHI) and integrated management of childhood illness (IMCI) provide opportunities for the introduction of some form of NHS in many of these countries where routine or systematic childhood hearing screening does not exist. Limited funding, manpower shortages, inadequate support services, low public awareness and the uncertainty regarding the commitment from healthcare practitioners may present some challenges but these are not insurmountable. Pilot studies are necessary in each country to provide empirical data that will guide healthcare providers who wish to introduce such a programme at any level of healthcare delivery.

International variation in reported livebirth prevalence rates of Down syndrome, adjusted for maternal age

Reported livebirth prevalence of Down syndrome (DS) may be affected by the maternal age distribution of the population, completeness of ascertainment, accuracy of diagnosis, extent of selective prenatal termination of affected pregnancies, and as yet unidentified genetic and environmental factors. To search for evidence of the latter, we reviewed all published reports in which it was possible to adjust both for effects of maternal age and for selective termination (where relevant). We constructed indices that allowed direct comparisons of prevalence rates after standardising for maternal age. Reference rates were derived from studies previously identified as having near complete ascertainment. An index value significantly different from 1 may result from random fluctuations, as well as from variations in the factors listed above. We found 49 population groups for which an index could be calculated. Methodological descriptions suggested that low values could often be attributed to under-ascertainment. A possible exception concerned African-American groups, though even among these most acceptable studies were compatible with an index value of 1. As we have reported elsewhere, there was also a suggestive increase in rates among US residents of Mexican or Central American origin. Nevertheless, our results suggest that "real" variation between population groups reported to date probably amounts to no more than +/-25%. However, reliable data in many human populations are lacking including, surprisingly, some jurisdictions with relatively advanced health care systems. We suggest that future reports of DS livebirth prevalence should routinely present data that allow calculation of an index standardised for maternal age and adjusted for elective prenatal terminations.

Syndromes, communicative disorders, and black children

Birth defects increase the risk of speech, language, and hearing disorders in childhood. The prevalence of particular congenital anomalies varies from one racial and ethnic group to another. Some conditions such as the hemoglobinopathies, polydactyly, and external ear malformations are more common among black people. Other birth defects are rarer among black children, notably cleft lip and palate, neural tube defects, and phenylketonuria. The more common defects of Down's syndrome, neurofibromatosis, and cerebral palsy appear to occur in equal frequency in black and white Americans.Speech-language pathologists, audiologists, and other health professionals who work with black children with birth defects must be familiar with the special problems and the positive features reflected in this population. Difficulties in obtaining adequate medical care, poor health and nutrition, and inadequate financial support are problems plaguing the poor. However, the shared responsibility assumed by the church, the community, and the extended family often results in positive acceptance of the handicapped child. Many families rely on folk medicine whose remedies can often be combined with traditional therapies for the ultimate benefit of the patient.Health professionals must assume a managerial role to ensure that services reach the child with syndrome-related speech, language, and hearing problems.