Aim-To describe 21 cases of symptomatic rickets in adolescents. Methods-The setting was a primary and secondary care hospital in Saudi Arabia providing medical care to Saudi Arab company employees and their families. Cases of symptomatic rickets diagnosed between January 1996 and December 1997 in adolescents aged 10 to 15 years were assessed with respect to clinical presentation, biochemical and radiological evaluation, dietary assessment, and estimation of sun exposure. Results-Symptomatic rickets developed in 21 adolescents (20 females), with a prevalence rate of 68 per 100 000 children years. Presentation included carpopedal spasms (n = 12), diVuse limb pains (n = 6), lower limbs deformities (n = 2), and generalised weakness (n = 1). Biochemical findings included hypocalcaemia (n = 19), hypophosphoraemia (n = 9), raised serum alkaline phosphatase (n = 21) and parathormone (n = 7), and reduced 25-hydroxyvitamin D concentrations (n = 7). Radiological studies were suggestive of rickets in only eight children. All children had an inadequate dietary calcium and vitamin D intake. All but one had less than 60 minutes sun exposure per day. Conclusion-Even in sunny climates, adolescents, especially females, can be at risk of rickets. Hypocalcaemic tetany and limb pains were the most common presenting symptoms. Radiological evidence was not present in every case. (Arch Dis Child 2001;84:501-503)

Background Ventricular septal defects (VSDs) are malformations in the septum separating the heart’s ventricles. VSDs may present as a single anomaly (isolated/nonsyndromic VSD) or as part of a group of phenotypes (syndromic VSD). The exact location of the defect is crucial in linking the defect to the underlying genetic cause. The number of children visiting cardiac surgery units is constantly increasing. However, there are no representative data available on the genetics of VSDs in Pakistani children. Methods Two hundred forty-two subjects (121 VSD children and 121 healthy controls) were recruited from pediatric cardiac units of Lahore. The clinical and demographic data of the subjects were collected. A total of four SNPs, one each from MTRR, GATA4, VEGF, and ISL1 genes were genotyped by PCR-RFLP. Results The results showed that the minor allele (T) frequency (MAFs) for the MTRR gene variant rs1532268 (c.524C > T) was 0.20 and 0.41 in the controls and the cases, respectively, with the genotype frequencies 3, 35, 62% in the controls and 12, 59 and 29% in the cases for TT, CT, CC genotypes, respectively (allelic OR: 5.73, CI: 3.82–8.61, p-value: 5.11 × 10− 7). For the GATA4 variant rs104894073 (c.886G > A), the MAF for the controls and the cases was 0.16 and 0.37, respectively, the frequencies of AA, GA and GG genotypes were 2, 28, and 70% in the controls and 5, 64 and 31% of the cases (allelic OR: 3.08, CI: 2.00–4.74, p-value: 8.36 × 10− 8). The rs699947 (c.-2578C > A) of VEGF gene showed MAF 0.36 and 0.53 for the controls and cases, respectively, with the genotype frequencies 13, 42, and 45% in the controls and 22, 15, and 63% in the cases for the AA, CA, CC (allelic OR: 2.03, CI: 1.41–2.92, p-value: 0.0001). The ISL1 gene variant rs6867206 (g.51356860 T > C), the MAFs were 0.26 and 0.31 in the controls and cases, respectively. The genotype frequencies were 48, 52, 0% in the controls and 39, 61, 0% in the cases for TT, TC, CC genotypes (allelic OR: 0.27, CI: 0.85–1.89, p-value: 0.227). The MTRR, GATA4 and VEGF variants showed association while ISL1 variant did not appear to be associated with the VSD in the recruited cohort. Conclusion This first report in Pakistani children demonstrates that single nucleotide polymorphisms in genes encoding transcription factors, signaling molecules and structural heart genes involved in fetal heart development are associated with developmental heart defects., however further work is needed to validate the results of the current investigation.

Background Cardiac morphogenesis is a dynamic and complex process that involves a complex interaction of many genetic and environmental factors. Ventricular septal defects (VSDs) are the commonest congenital heart defects (CHDs), accounting for ~ 40% of all cardiac malformations. In Pakistan, the prevalence of VSD is increasing (4–6 in 1000 live births). In the current study, we aimed to determine the pattern of different hematological parameters and various risk factors in VSDs in local pediatric patients. We recruited the clinically diagnosed VSD children (n = 125) from various hospitals. The diagnosis was made based on echocardiography, size, number, and exact location of the defect. Hematological parameters, chemical pathological assays, and liver function analysis were performed. The blood group distribution and various risk factors were also assessed. The statistical analysis was done using the SPSS (IBM statistics version 22) software. Results The results showed that for RBCs, 20% of patients in category of 0 to 3 months are above normal range; for WBCs, 33.3% of patients are above normal range in category of 4–5 years and 12–14 years. For hemoglobin, highest percentage of patients was observed below normal range; 30% of patients in category of 0 to 3 months, 40% of patients in category 4–9 months, 35.2% of patients in category of 10 months–3 years, and 33.3% of patients in category of 12–14 years were below normal range. For platelet count, 5.66% patients were below normal range and 16.9% were above normal range. For prothrombin time (PT) and activated partial thromboplastin time (APTT) more than 90% patients were in normal range value. Elevated ALP level and significantly lower albumin levels were observed. In age range of 13–14 years, 50% patients were below range for both calcium and serum creatinine. The prevalence of cousin marriages was 62.3%, about 60% mothers used antibiotics during pregnancy, B + ve and O + ve had the highest frequencies, and most of the patients were seen in age group of 2–35 months. Conclusion All tested parameters show divergence from normal values their predictive capabilities of VSDs. To the best of our knowledge, the present study is the first to report data on hematological parameters and demographic risk factor associated with VSDs, in the Pakistani children. This data may have implication on the characterization and diagnosis of VSDs as well as on the assessment of related risk factors.

COVID-19 research has relied heavily on convenience-based samples, which—though often necessary—are susceptible to important sampling biases. We begin with a theoretical overview and introduction to the dynamics that underlie sampling bias. We then empirically examine sampling bias in online COVID-19 surveys and evaluate the degree to which common statistical adjustments for demographic covariates successfully attenuate such bias. This registered study analysed responses to identical questions from three convenience and three largely representative samples (total N = 13,731) collected online in Canada within the International COVID-19 Awareness and Responses Evaluation Study ( www.icarestudy.com ). We compared samples on 11 behavioural and psychological outcomes (e.g., adherence to COVID-19 prevention measures, vaccine intentions) across three time points and employed multiverse-style analyses to examine how 512 combinations of demographic covariates (e.g., sex, age, education, income, ethnicity) impacted sampling discrepancies on these outcomes. Significant discrepancies emerged between samples on 73% of outcomes. Participants in the convenience samples held more positive thoughts towards and engaged in more COVID-19 prevention behaviours. Covariates attenuated sampling differences in only 55% of cases and increased differences in 45%. No covariate performed reliably well. Our results suggest that online convenience samples may display more positive dispositions towards COVID-19 prevention behaviours being studied than would samples drawn using more representative means. Adjusting results for demographic covariates frequently increased rather than decreased bias, suggesting that researchers should be cautious when interpreting adjusted findings. Using multiverse-style analyses as extended sensitivity analyses is recommended. Supplementary Information The online version contains supplementary material available at 10.1007/s10654-022-00932-y.