Genetic Susceptibility to Drug Teratogenicity: A Systematic Literature Review

The first review on prenatal drug exposure and ocular malformation occurrence

Even though a non-negligible portion of congenital eye anomalies has a clear genetic origin, an etiology is not found for most patients. Prenatal medication exposure is recognized to be involved in fetal malformations and several medications are specifically known to alter eye morphogenesis during embryonic development leading to congenital eye defects. We explored and reviewed the role of medications described in the genesis of ocular malformations, a role that has been little evaluated and probably still underestimated especially since several studies have shown the wide exposure of pregnant women to medication. We present our results in two sections; the first describes medications reported to be associated with ocular malformations in humans; the second details medications responsible for ocular malformations in animal models. We have summarized these results in tables, providing a relevant tool for clinicians. As most of the associations between medication exposure and congenital eye defects are either old or single case reports, this study highlights the needs for high epidemiological vigilance, accurate clinical description as well as a combination of studies on human genetics and experimental studies. Since medication exposures are potentially modifiable risk factors for congenital anomalies, this represents an important opportunity to implement preventive measures.

Study of nitrogen heterocycles as DNA/HSA binder, topoisomerase inhibitors and toxicological safety

Four new nitrogen-containing heterocyclic derivatives (acridine, quinoline, indole, pyridine) were synthesized and their biological properties were evaluated. The compounds showed affinity for DNA and HSA, with CAIC and CAAC displaying higher binding constants (Kb) of 9.54 × 104 and 1.06 × 106, respectively. The fluorescence quenching assay (Ksv) revealed suppression values ranging from 0.34 to 0.64 × 103 M-1 for ethidium bromide (EB) and 0.1 to 0.34 × 103 M-1 for acridine orange (AO). Molecular docking confirmed the competition of the derivatives with intercalation probes at the same binding site. At 10 μM concentrations, the derivatives inhibited topoisomerase IIα activity. In the antiproliferative assays, the compounds demonstrated activity against MCF-7 and T47-D tumor cells and nonhemolytic profile. Regarding toxicity, no acute effects were observed in the embryos. However, some compounds caused enzymatic and cardiac changes, particularly the CAIC, which increased SOD activity and altered heart rate compared to the control. These findings suggest potential antitumor action of the derivatives and indicate that substituting the acridine core with different cores does not interfere with their interaction and topoisomerase inhibition. Further investigations are required to assess possible toxicological effects, including reactive oxygen species generation.

Surfacing undiagnosed disease: consideration, counting and coding

The diagnostic odyssey for people living with rare diseases (PLWRD) is often prolonged for myriad reasons including an initial failure to consider rare disease and challenges to systemically and systematically identifying and tracking undiagnosed diseases across the diagnostic journey. This often results in isolation, uncertainty, a delay to targeted treatments and increase in risk of complications with significant consequences for patient and family wellbeing. This article aims to highlight key time points to consider a rare disease diagnosis along with elements to consider in the potential operational classification for undiagnosed rare diseases during the diagnostic odyssey. We discuss the need to create a coding framework that traverses all stages of the diagnostic odyssey for PLWRD along with the potential benefits this will have to PLWRD and the wider community.

Chemical composition, health benefits and future prospects of Paulownia flowers: A review

The plants of the genus Paulownia (Scrophulariaceae) have been gaining attention for wood production, and their flowers, which are a seasonal by-product, have been traditionally used in medicinal products. The phytochemistry and pharmacology of Paulownia flowers contribute to their economic uses in medicines, foods, animal feeds, and cosmetics. The chemical composition of Paulownia flowers is mostly flavonoids, phenylpropanoids, terpenoids, volatile components, polysaccharides, lignans, and iridoids, which exhibit various health benefits, such as antioxidant, anti-inflammatory, antibacterial, antiviral, anticancer, hypoglycemic, hypolipidemic, neuroprotective and immunoregulation activities. Moreover, the extracts of the Paulownia flower have been proven safe for animals. These promote the development of new products and technologies using Paulownia flowers, with intellectual property rights. The review presents the current developments on the chemical composition, biological and pharmacological activities, and economic values of Paulownia flowers, and aims to provide a reference for their further utilization.

An update on teratogens for pediatric healthcare providers

PURPOSE OF REVIEW

To review updates regarding teratogens and give pediatric healthcare providers insight into the prevention of teratogenic exposures.

RECENT FINDINGS

Application of the principles of teratology can help to assess the potential for exposures to be teratogenic. Identification of Zika virus as a teratogen, the most recent teratogenic agent identified, allowed public health measures to be put in place to mitigate its spread. Risk management strategies for teratogenic medications have resulted in a decrease but often not elimination of prenatal exposures. The failure to include pregnant persons in clinical trials results in their being less likely to receive needed medications and vaccines in a timely manner.

SUMMARY

Pediatricians play an important role in the prevention of teratogenic exposures. Ensuring optimal management of patients with chronic illnesses that might increase their risk of birth defects during pregnancy due to the illness itself or its treatment is essential. For patients with pregnancy potential who are on teratogenic medications, ensuring effective contraception is also important. Inclusion of pregnant persons in clinical trials and research studies will be critical to advancing our knowledge of the safety of medications and other exposures during pregnancy.

Genetic evaluation of HAND2 gene and its effects on thalidomide embryopathy

BACKGROUND

HAND2 is a transcription factor important for embryonic development, required for limbs and cardiovascular development. Thalidomide is a drug responsible to a spectrum of congenital anomalies known as Thalidomide Embryopathy (TE), which includes mainly limb and heart defects. It is known that HAND2 interaction with TBX5, an important protein for limbs and heart development, is inhibited by Thalidomide. The aim of this study was to evaluate and characterize HAND2 in the context of TE, and to evaluate its variability in TE individuals.

METHODS

DNA from 35 TE subjects was extracted from saliva samples and PCR was performed for amplification and Sanger sequencing of HAND2 coding sequence.

RESULTS

The analysis showed only one variant; a synonymous variant p.P51 (rs59621536) in exon 1 found in three individuals. Further in silico evaluation confirmed highly HAND2 conservation, being the 3'UTR the most polymorphic region of the gene. Additional computational analyses classified the variant as neutral, without alteration in splicing and miRNA sites. In silico predictions pointed to alteration of two CpG islands adjacent to the variant; however, we did not observe any alterations on the methylation pattern of HAND2 gene in our sample. Moreover, alteration of the binding site of MeCP2, a nuclear protein involved in DNA methylation, was predicted along with alteration in HAND2 mRNA structure.

CONCLUSIONS

Considering HAND2 being a well conserved gene, further studies with a larger sample should be performed to evaluate the role this gene on genetic susceptibility to TE.

Maternal genetic factors in the development of congenital heart defects

Congenital heart defects (CHDs) are among the most common, serious birth defects. However, the cause of CHDs is unknown for approximately half of affected individuals and there are few prevention strategies. Although not extensively investigated, maternal genes may contribute to CHD etiology by modifying the effects of maternal exposures (e.g. medications, nutrients), contributing to maternal phenotypes that are associated with an increased risk of CHDs in offspring (e.g. diabetes), or acting as maternal effect genes. Since maternal genes could serve as a target for the primary prevention of CHDs, efforts to further define the contribution of the maternal genome to CHD etiology are warranted.

Transcriptome meta-analysis of valproic acid exposure in human embryonic stem cells

Valproic acid (VPA) is a widely used antiepileptic drug not recommended in pregnancy because it is teratogenic. Many assays have assessed the impact of the VPA exposure on the transcriptome of human embryonic stem-cells (hESC), but the molecular perturbations that VPA exerts in neurodevelopment are not completely understood. This study aimed to perform a transcriptome meta-analysis of VPA-exposed hESC to elucidate the main biological mechanisms altered by VPA effects on the gene expression. Publicly available microarray and RNA-seq transcriptomes were selected in the Gene Expression Omnibus (GEO) repository. Samples were processed according to the standard pipelines for each technology in the Galaxy server and R. Meta-analysis was performed using the Fisher-P method. Overrepresented genes were obtained by evaluating ontologies, pathways, and phenotypes' databases. The meta-analysis performed in seven datasets resulted in 61 perturbed genes, 54 upregulated. Ontology and pathway enrichments suggested neurodevelopment and neuroinflammatory effects; phenotype overrepresentation included epilepsy-related genes, such as SCN1A and GABRB2. The NDNF gene upregulation was also identified; this gene is involved in neuron migration and survival during development. Sub-network analysis proposed TGFβ and BMP pathways activation. These results suggest VPA exerts effects in epilepsy-related genes even in embryonic cells. Neurodevelopmental genes, such as NDNF were upregulated and VPA might also disturb several development pathways. These mechanisms might help to explain the spectrum of VPA-induced congenital anomalies and the molecular effects on neurodevelopment.

Chronic Myeloid Leukemia and Pregnancy: When Dreams Meet Reality. State of the Art, Management and Outcome of 41 Cases, Nilotinib Placental Transfer

The overwhelming success of tyrosine kinase inhibitor (TKI) therapy in chronic myeloid leukemia (CML) patients has opened a discussion among medical practitioners and the lay public on the real possibility of pregnancy and conception in females and males with CML. In the past 10 years this subject has acquired growing interest in the scientific community and specific knowledge has been obtained "from bench to bedside". Embryological, pharmacological, and pathophysiological studies have merged with worldwide patient databases to provide a roadmap to a successful pregnancy and birth in CML patients. Male conception does not seem to be affected by TKI therapy, since this class of drugs is neither genotoxic nor mutagenic, however, caution should be used specially with newer drugs for which little or no data are available. In contrast, female patients should avoid TKI therapy specifically during the embryonic stage of organogenesis (5-12 weeks) because TKIs can be teratogenic. In the last 15 years, 41 pregnancies have been followed in our center. A total of 11 male conceptions and 30 female pregnancies are described. TKI treatment was generally terminated as soon as the pregnancy was discovered (3-5 weeks), to avoid exposure during embryonic period and to reduce the risk of needing treatment in the first trimester. Eleven pregnancies were treated with interferon, imatinib or nilotinib during gestation. Nilotinib plasma levels in cord blood and maternal blood at delivery were studied in 2 patients and reduced or absent placental crossing of nilotinib was observed. All of the patients were managed by a multidisciplinary team of physicians with obligatory hematological and obgyn consultations. This work provides an update on the state of the art and detailed description of pregnancy management and outcomes in CML patients.

Analysis of Gene-Environment Interactions Related to Developmental Disorders

Various genetic and environmental factors are associated with developmental disorders (DDs). It has been suggested that interaction between genetic and environmental factors (G × E) is involved in the etiology of DDs. There are two major approaches to analyze the interaction: genome-wide and candidate gene-based approaches. In this mini-review, we demonstrate how these approaches can be applied to reveal the G × E related to DDs focusing on zebrafish and mouse models. We also discuss novel approaches to analyze the G × E associated with DDs.