The human face is a complex assemblage of highly variable yet clearly heritable anatomic structures that together make each of us unique, distinguishable, and recognizable. Relatively little is known about the genetic underpinnings of normal human facial variation. To address this, we carried out a large genomewide association study and two independent replication studies of Bantu African children and adolescents from Mwanza, Tanzania, a region that is both genetically and environmentally relatively homogeneous. We tested for genetic association of facial shape and size phenotypes derived from 3D imaging and automated landmarking of standard facial morphometric points. SNPs within genes SCHIP1 and PDE8A were associated with measures of facial size in both the GWAS and replication cohorts and passed a stringent genomewide significance threshold adjusted for multiple testing of 34 correlated traits. For both SCHIP1 and PDE8A, we demonstrated clear expression in the developing mouse face by both whole-mount in situ hybridization and RNA-seq, supporting their involvement in facial morphogenesis. Ten additional loci demonstrated suggestive association with various measures of facial shape. Our findings, which differ from those in previous studies of European-derived whites, augment understanding of the genetic basis of normal facial development, and provide insights relevant to both human disease and forensics.

BackgroundCongenital anomalies or birth defects are among the leading causes of infant mortality and morbidity around the world. The impact of congenital anomalies is particularly severe in middle- and low-income countries where health care resources are limited. The prevalence of congenital anomalies varies in different parts of the world, which could reflect different aetiological factors in different geographical regions.MethodsBetween October 2012 and January 2013, a cross-sectional study was conducted involving young infants below 2 months of age, admitted at a university teaching hospital in Tanzania. Face-to-face interviews with parents/caretakers of young infants were carried out to collect socio-demographic and clinical information. Physical examinations were performed on all young infants. Echocardiography, X-ray, cranial as well as abdominal ultrasonographies were performed when indicated.ResultsAnalysis of the data showed that among 445 young infants enrolled in the study, the prevalence of congenital anomalies was 29%, with the Central Nervous System (CNS) as the most commonly affected organ system. Maternal factors that were significantly associated with congenital anomalies included the lack of peri-conceptional use of folic acid (OR = 3.1; 95% CI = 1.4-6.7; p = 0.005), a maternal age of above 35 years (OR = 2.2; 95% CI = 1.1-4.3; p = 0.024) and an inadequate attendance to antenatal clinic (OR = 2.1; 95% CI = 1.4-3.3; p < 0.001). Infant factors that were significantly associated with congenital anomalies were female sex, a birth weight of 2.5 kg or more, singleton pregnancy and a birth order above 4.ConclusionsDue to the high prevalence of congenital anomalies observed in this particular context, the hospital should mobilize additional resources for an optimal and timely management of the patients with congenital anomalies. In this study, the proportion of women taking folic acid supplements during early pregnancy was very low. Efforts should be made to ensure that more women use folic acid during the peri-conceptional period, as the use of folic acid supplement has been linked by several authors to a reduced occurrence of some congenital anomalies.

BackgroundThe use of cadavers in human anatomy teaching requires adequate number of anatomy instructors who can provide close supervision of the students. Most medical schools are facing challenges of lack of trained individuals to teach anatomy. Innovative techniques are therefore needed to impart adequate and relevant anatomical knowledge and skills. This study was conducted in order to evaluate the traditional teaching method and reciprocal peer teaching (RPT) method during anatomy dissection.MethodsDebriefing surveys were administered to the 227 first year medical students regarding merits, demerits and impact of both RPT and Traditional teaching experiences on student’s preparedness prior to dissection, professionalism and communication skills. Out of this, 159 (70 %) completed the survey on traditional method while 148 (65.2 %) completed survey on RPT method. An observation tool for anatomy faculty was used to assess collaboration, professionalism and teaching skills among students. Student’s scores on examinations done before introduction of RPT were compared with examinations scores after introduction of RPT.ResultsOur results show that the mean performance of students on objective examinations was significantly higher after introduction of RPT compared to the performance before introduction of RPT [63.7 ± 11.4 versus 58.6 ± 10, mean difference 5.1; 95 % CI = 4.0–6.3; p-value < 0.0001]. Students with low performance prior to RPT benefited more in terms of examination performance compared to those who had higher performance [Mean difference 7.6; p-value < 0.0001]. Regarding student’s opinions on traditional method versus RPT, 83 % of students either agreed or strongly agreed that they were more likely to read the dissection manual before the RPT dissection session compared to 35 % for the traditional method. Over 85 % of respondents reported that RPT improved their confidence and ability to present information to peers and faculty compared to 38 % for the tradition method. The majority of faculty reported that the learning environment of the dissection groups was very active learning during RPT sessions and that professionalism was observed by most students during discussions.ConclusionsIntroduction of RPT in our anatomy dissection laboratory was generally beneficial to both students and faculty. Both objective (student performance) and subjective data indicate that RPT improved student’s performance and had a positive learning experience impact. Our future plan is to continue RPT practice and continually evaluate the RPT protocol.

BackgroundClefts of the lip (CL), the palate (CP), or both (CLP) are the most common orofacial congenital malformations found among live births, accounting for 65% of all head and neck anomalies. The frequency and pattern of orofacial clefts in different parts of the world and among different human groups varies widely. Generally, populations of Asian or Native American origin have the highest prevalence, while Caucasian populations show intermediate prevalence and African populations the lowest. To date, little is known regarding the epidemiology and pattern of orofacial clefts in Tanzania.MethodsA retrospective descriptive study was conducted at Bugando Medical Centre to identify all children with orofacial clefts that attended or were treated during a period of five years. Cleft lip and/or palate records were obtained from patient files in the Hospital's Departments of Surgery, Paediatrics and medical records. Age at presentation, sex, region of origin, type and laterality of the cleft were recorded. In addition, presence of associated congenital anomalies or syndromes was recorded.ResultsA total of 240 orofacial cleft cases were seen during this period. Isolated cleft lip was the most common cleft type followed closely by cleft lip and palate (CLP). This is a departure from the pattern of clefting reported for Caucasian and Asian populations, where CLP or isolated cleft palate is the most common type. The distribution of clefts by side showed a statistically significant preponderance of the left side (43.7%) (χ2 = 92.4, p < 0.001), followed by the right (28.8%) and bilateral sides (18.3%). Patients with isolated cleft palate presented at very early age (mean age 1.00 years, SE 0.56). Associated congenital anomalies were observed in 2.8% of all patients with orofacial clefts, and included neural tube defects, Talipes and persistent ductus arteriosus.ConclusionsUnilateral orofacial clefts were significantly more common than bilateral clefts; with the left side being the most common affected side. Most of the other findings did not show marked differences with orofacial cleft distributions in other African populations.

The human face is an array of variable physical features that together make each of us unique and distinguishable. Striking familial facial similarities underscore a genetic component, but little is known of the genes that underlie facial shape differences. Numerous studies have estimated facial shape heritability using various methods. Here, we used advanced three-dimensional imaging technology and quantitative human genetics analysis to estimate narrow-sense heritability, heritability explained by common genetic variation, and pairwise genetic correlations of 38 measures of facial shape and size in normal African Bantu children from Tanzania. Specifically, we fit a linear mixed model of genetic relatedness between close and distant relatives to jointly estimate variance components that correspond to heritability explained by genome-wide common genetic variation and variance explained by uncaptured genetic variation, the sum representing total narrow-sense heritability. Our significant estimates for narrow-sense heritability of specific facial traits range from 28 to 67%, with horizontal measures being slightly more heritable than vertical or depth measures. Furthermore, for over half of facial traits, .90% of narrow-sense heritability can be explained by common genetic variation. We also find high absolute genetic correlation between most traits, indicating large overlap in underlying genetic loci. Not surprisingly, traits measured in the same physical orientation (i.e., both horizontal or both vertical) have high positive genetic correlations, whereas traits in opposite orientations have high negative correlations. The complex genetic architecture of facial shape informs our understanding of the intricate relationships among different facial features as well as overall facial development.

Biomonitoring studies of vulnerable populations in low‐ and middle‐income countries are limited because traditional sampling methods are challenging to implement in low‐resource settings. The present study examined the feasibility, precision, and accuracy of dried blood spots (DBS) for human biomonitoring of nonessential elements (cadmium [Cd], mercury [Hg], and lead [Pb]) in an area of northern Tanzania with artisanal and small‐scale gold mining activities. Pregnant women (n = 44) were recruited in Geita during antenatal clinic visits, and DBS from capillary blood were collected on filter paper. As a gold‐standard comparison, venous blood was sampled from the same participants and compared with the DBS. Venous blood, DBS, and quality control samples were analyzed for chemical elements by inductively coupled plasma mass spectrometry. Field blanks were very clean for most elements, generally only twice as high as corresponding laboratory filter blanks. No significant differences were found between duplicate DBS samples taken from the same participants, with near perfect intraclass correlation coefficients (0.99) for Cd, Hg, and Pb, indicating excellent reliability. Moreover, correlation was strong (r2 > 0.9) and significant (p < 0.0001) between DBS and the quantitative venous blood, with regression line slopes close to 1.0 (0.847, 0.976, and 0.969 for Cd, Hg, and Pb, respectively), indicating high accuracy of the DBS method compared with the gold‐standard approach. The DBS method is minimally invasive and was a feasible, precise, and accurate means of measuring exposure to Cd, Hg, and Pb in pregnant women in a low‐resource setting. Environ Toxicol Chem 2019;38:1285–1293. © 2019 SETAC

BackgroundInfantile hypertrophic pyloric stenosis (IHPS) is the most common cause of gastric outlet obstruction in infants. There is paucity of published data regarding this condition in our setting. This study describes the clinical presentation, mode of treatment and outcome of treatment of this disease and identifies factors responsible for poor outcome of these patients.MethodsThis was a descriptive retrospective study of infants with HPS admitted to Bugando Medical Centre and subsequently underwent surgery between February 2009 and January 2014.ResultsA total of 102 patients (M:F = 4.7:1) were studied. The median age at presentation was 5 weeks. The median duration of illness was 4 weeks. Fifty-four (52.9 %) patients occur in first-born children. Associated anomalies were reported in 7 (6.9 %) patients. Non-bilious vomiting was the most frequent symptom and it was described in all (100 %) patients. A palpable mass was found in 23.5 % of infants. The diagnosis of IHPS was made clinically in 86 (84.3 %) and by ultrasound in 16 (15.7 %) patients. The treatment was Ramstedt’s pyloromyotomy in all cases. There were 6 (5.9 %) intra-operative mucosal perforations which were repaired successively. Postoperative complication was 11.8 %. The median length of hospital stay was 12 days and it was significantly associated with prolonged pre-operative hospitalization (p = 0.001). The mortality rate was 4.9 %. Age below 2 weeks, late presentation (≥14 days), severe dehydration on admission, hypokalaemia on admission and surgical site infection were the main predictors of mortality (p < 0.001).ConclusionThis study has shown that IHPS is a common condition in our setting. Age <2 weeks, delayed presentation, prolonged preoperative hospital stay, surgical site infection and high proportion of dehydration and electrolyte disturbance were the main predictors of poor outcome. A high index of suspicion is needed in infants with non-bilious vomiting to avoid delay in diagnosis.

BackgroundHirschsprung’s disease (HD) is the commonest cause of functional intestinal obstruction in children and poses challenges to pediatricians and pediatric surgeons practicing in resource-limited countries. This study describes the clinical characteristics and outcome of management of this disease in our setting and highlights challenges associated with the care of these patients and proffer solutions for improved outcome.MethodsThis was a descriptive prospective study of children aged ≤ 10 years who were histologically diagnosed and treated for HD at our centre between July 2008 and June 2013.ResultsA total of 110 patients (M: F ratio= 3.6:1) with a median age of 24 months were studied. Six (5.5%) patients were in the neonatal period. Sixty-four (58.2%) patients had complete intestinal obstruction whereas 42 (38.2%) and 4 (3.6%) patients had chronic intestinal obstruction and intestinal perforation respectively. No patient had enterocolitis. Constipation (94.5%) was the most common complaints. 109 (99.1%) patients had colostomy prior to the definitive pull-through. The median duration of colostomy before definitive pull-through was 4 months. The majority of patients (67.3%) had short segment of aganglionosis localized to the recto-sigmoid region. The definitive pull-through was performed in 94 (85.5%) patients (Swenson’s pull-through 76 (80.9%), Duhamel’s pull-through (12.8%) and Soave’s pull-through 4 (4.3%) patients). Postoperative complication rate was 47.3%. The median length of hospital stay was 26 days. Patients who developed complications stayed longer in the hospital and this was statistically significant (p <0.001). Mortality rate was 21.8%. The age < 4 weeks, delayed presentation and surgical site infection were the main predictors of mortality (p < 0.001). During the follow-up period, the results of Swenson’s and Duhamel’s pull through procedures were generally good in 87.8% and 42.9% of patients respectively. The result of Soave’s procedures was generally poor in this study.ConclusionHD remains the commonest cause of functional intestinal obstruction in children and contributes significantly to high morbidity and mortality in our setting. The majority of patients present late when the disease becomes complicated. Early diagnosis and timely definitive pull through procedure are essential in order to decrease the morbidity and mortality associated with this disease.