A morpho-etiological description of congenital limb anomalies

Unraveling the Challenges: A Critical Review of Congenital Malformations in Low Socioeconomic Strata of Developing Countries

Congenital malformations pose significant challenges in the low socioeconomic strata of developing countries. This review critically examines the prevalence, patterns, and factors influencing congenital malformations in these settings. It explores the physical, psychological, and economic consequences for affected individuals and their families and the social stigma and discrimination they face. The review highlights the importance of equity and access to healthcare services, the role of environmental factors and nutritional deficiencies, and the ethical considerations and policy implications associated with congenital malformations. Existing interventions, challenges in implementation, and innovative approaches are discussed. Gaps in knowledge and areas for further research are identified. Addressing congenital malformations in low socioeconomic strata requires multidisciplinary collaboration, advocacy, and inclusive policies. By prioritizing preventive measures, early detection, and comprehensive care, the burden of congenital malformations can be reduced, improving the quality of life for affected individuals and their communities.

In-utero vascular accidents in neonates from COVID-19 infected mothers

PURPOSE

Infection with COVID-19 during pregnancy has been associated with a hypercoagulable state. It is unknown if maternal COVID-19 infection results in congenital anomalies secondary to intrauterine vascular accidents. This study sought to determine if the rate of in-utero vascular complications (intestinal atresia and limb abnormalities) that may be attributable to the hypercoagulable states associated with COVID-19 and pregnancy increased after the onset of the pandemic.

METHODS

Pregnancy, neonatal, and congenital defect data from a single academic medical center and the partner's children's hospital were collected and compared to the period prior to onset of the pandemic. A subanalysis including pregnant woman 18 years or greater with documented COVID-19 infection during gestation between March 2020-2021 was performed.

RESULTS

Rates of intestinal atresia did not differ prior to or after the onset of the pandemic (3.78% vs 7.23%, p = 0.21) nor did rates of limb deficiency disorders (4.41% vs 9.65%, p = 0.09). On subanalysis, there were 194 women with COVID-19 infection included in analysis: 135 (69.6%) were positive during delivery admission and 59 (30.4%) were positive earlier in their pregnancy. There was one infant born with intestinal atresia.

CONCLUSION

We report a low incidence of congenital anomalies in infants born to mothers with COVID-19 infection. It remains unclear if the impact of COVID-19 on the coagulative state augments the normal pro-thrombotic state of pregnancy; ongoing surveillance is warranted.

A 50-kb deletion disrupting the RSPO2 gene is associated with tetradysmelia in Holstein Friesian cattle

Background

Tetradysmelia is a rare genetic disorder that is characterized by an extremely severe reduction of all limb parts distal of the scapula and pelvic girdle. We studied a Holstein Friesian backcross family with 24 offspring, among which six calves displayed autosomal recessive tetradysmelia. In order to identify the genetic basis of the disorder, we genotyped three affected calves, five dams and nine unaffected siblings using a Bovine Illumina 50 k BeadChip and sequenced the whole genome of the sire.

Results

Pathological examination of four tetradysmelia cases revealed a uniform and severe dysmelia of all limbs. Applying a homozygosity mapping approach, we identified a homozygous region of 10.54 Mb on chromosome 14 (Bos taurus BTA14). Only calves that were diagnosed with tetradysmelia shared a distinct homozygous haplotype for this region. We sequenced the whole genome of the cases’ sire and searched for heterozygous single nucleotide polymorphisms (SNPs) and small variants on BTA14 that were uniquely present in the sire and absent from 3102 control whole-genome sequences of the 1000 Bull Genomes Project, but none were identified in the 10.54-Mb candidate region on BTA14. Therefore, we subsequently performed a more comprehensive analysis by also considering structural variants and detected a 50-kb deletion in the targeted chromosomal region that was in the heterozygous state in the cases’ sire. Using PCR, we confirmed that this detected deletion segregated perfectly within the family with tetradysmelia. The deletion spanned three exons of the bovine R-spondin 2 (RSPO2) gene, which encode three domains of the respective protein. R-spondin 2 is a secreted ligand of leucine-rich repeats containing G protein-coupled receptors that enhance Wnt signalling and is involved in a broad range of developmental processes during embryogenesis.

Conclusions

We identified a 50-kb deletion on BTA14 that disrupts the coding sequence of the RSPO2 gene and is associated with bovine tetradysmelia. To our knowledge, this is the first reported candidate causal mutation for tetradysmelia in a large animal model. Since signalling pathways involved in limb development are conserved across species, the observed inherited defect may serve as a model to further elucidate fundamental pathways of limb development.

Classification of congenital upper limb anomalies: towards improved communication, diagnosis, and discovery

Recently the International Federation of Societies for Surgery of the Hand replaced the Swanson scheme for classifying congenital upper limb anomalies with the Oberg, Manske, Tonkin (OMT) classification. This review explores the reasons for this change after nearly 50 years of using the Swanson classification. In particular, it documents the state of our understanding regarding genetics and limb development at the time Swanson generated his classification. It also describes the continued progress in clinical genetics and developmental biology. Such progress drives the need to embrace and incorporate these changes within a new classification scheme; one that will improve communication, diagnosis, and support further discovery of the pathogenesis of congenital hand anomalies.

Birth prevalence for congenital limb defects in the northern Netherlands: a 30-year population-based study

Background

Reported birth prevalences of congenital limb defects (CLD) vary between countries: from 13/10,000 in Finland for the period 1964–1977 to 30.4/10,000 births in Scotland from 1964–1968. Epidemiological studies permit the timely detection of trends in CLD and of associations with other birth defects. The aim of this study is to describe the birth prevalence of CLD in the northern Netherlands.

Methods

In a population-based, epidemiological study we investigated the birth prevalences of CLD for 1981–2010. Data were collected by the European Surveillance of Congenital Anomalies in the northern Netherlands (EUROCAT-NNL). We excluded malpositions, club foot, and dislocation/dysplasia of hips or knees. Trends were analysed for the 19-year period 1992–2010 using χ² tests, as well as CLD association with anomalies affecting other organs.

Results

The birth prevalence of CLD was 21.1/10,000 births for 1981–2010. There was an overall decrease in non-syndromic limb defects (P = 0.023) caused by a decrease in the prevalence of non-syndromic syndactyly (P < 0.01) in 1992–2010. Of 1,048 children with CLD, 55% were males, 57% had isolated defects, 13% had multiple congenital anomalies (MCA), and 30% had a recognised syndrome. The upper:lower limb ratio was 2:1, and the left:right side ratio was 1.2:1. Cardiovascular and urinary tract anomalies were common in combination with CLD (37% and 25% of cases with MCA). Digestive-tract anomalies were significantly associated with CLD (P = 0.016).

Conclusions

The birth prevalence of CLD in the northern Netherlands was 21.1/10,000 births. The birth prevalence of non-syndromic syndactyly dropped from 5.2/10,000 to 1.1/10,000 in 1992–2010.

The first case of Horn Kolb Syndrome in Turkey, diagnosed prenatally at the 23rd week of a pregnancy: A very rare and unusual case far from the original geography

Background:

The aim of this report was to evaluate and announce the first documented appearance of Horn Kolb syndrome in Turkey.

Case Report:

Acheiropodia (Horn Kolb Syndrome) is the bilateral congenital amputation of the distal parts of the 4 extremities. It is an autosomal recessive developmental disorder. The characteristic features are amputation of the upper and lower extremities with aplasia of the hands and feet. The disorder affects only the extremities without other systemic manifestations. In this report, we present the first known case of Horn Kolb syndrome in Turkey, along with the diagnostic features.

Conclusions:

Severe dysmorphic skeletal anomalies should be excluded as soon as the earlier gestational weeks in every pregnancy by visualizing all 4 limbs of the fetus in routine prenatal ultrasound screening.