Attention-deficit hyperactivity disorder (ADHD) is primarily a neurodevelopmental disorder affecting children. However, about two-thirds of those affected will continue to have the condition into adulthood and a small number of people are diagnosed as adults. The researchers found an increased number of autism risk variants in individuals with childhood ADHD compared to late-diagnosed ADHD and a larger genetic overlap of persistent and late-diagnosed ADHD with depression compared to childhood ADHD. Read more about this study under Article 1.
Contents
- Article 1: Differences in the genetic architecture of common and rare variants in childhood, persistent and late-diagnosed attention-deficit hyperactivity disorder
- Article 2: LINE-1 RNA causes heterochromatin erosion and is a target for amelioration of senescent phenotypes in progeroid syndromes
- Article 3: Integrating de novo and inherited variants in 42,607 autism cases identifies mutations in new moderate-risk genes
- Article 4: Maternal SMCHD1 regulates Hox gene expression and patterning in the mouse embryo
- References
Article 1: Differences in the genetic architecture of common and rare variants in childhood, persistent and late-diagnosed attention-deficit hyperactivity disorder
Genetics can influence the time that attention-deficit hyperactivity disorder (ADHD) is first diagnosed as well as its persistence into adulthood among affected children. ADHD is primarily a neurodevelopmental disorder affecting children. However, about two-thirds of those affected will continue to have the condition into adulthood and a small number of people are diagnosed as adults. The researchers found an increased number of autism risk variants in individuals with childhood ADHD compared to late-diagnosed ADHD and a larger genetic overlap of persistent and late-diagnosed ADHD with depression compared to childhood ADHD. In summary, they identified genetic heterogeneity among ADHD subgroups, suggesting that genetic factors influence the time of first ADHD diagnosis, persistence of ADHD into adulthood and comorbidity patterns. Read the full article here.
In summary: Genetics can influence the time that ADHD is first diagnosed and its persistence into adulthood
Article 2: LINE-1 RNA causes heterochromatin erosion and is a target for amelioration of senescent phenotypes in progeroid syndromes
A recent study found a link between long interspersed nuclear element 1 (LINE-1) retrotransposon elements and premature aging conditions called Hutchinson-Gilford syndrome and Werner syndrome. In progeroid syndromes*, LINE-1 RNA accumulates in cells. By preventing such accumulation, researchers could reduce premature age-related symptoms and alter the expression of genes in aging, inflammation, and other pathways in mouse models or human cells. In conclusion, targeting LINE-1 RNA may be an effective way to treat progeroid syndromes, as well as other age-related diseases that have been connected to LINE-1, including neuropsychiatric, eye, metabolic disorders, and cancers. Read the full article here.
*Progeroid syndromes are a group of rare genetic disorders that are characterized by signs of premature aging. Affected individuals appear to be older than they are.
In summary: Targeting LINE-1 RNA may be used to treat age-related diseases
Article 3: Integrating de novo and inherited variants in 42,607 autism cases identifies mutations in new moderate-risk genes
Researchers identified five new risk genes* for developing autism spectrum disorder (ASD), four of which they considered moderate risk genes. Several genes have been previously linked to ASD and as a group are responsible for about 20% of all cases. Most individuals who carry these genes have profound forms of ASD and additional neurological issues, such as epilepsy and intellectual disability. Individuals with ASD with variants in the newly identified four moderate risk genes (NAV3, ITSN1, SCAF1, and HNRNPUL2) had lower levels of cognitive impairment than that observed among individuals with ASD with other variants. Unlike previously known ASD genes, which are due to de novo mutations, genetic variants in the five new genes were often inherited from the participant’s parents. Read the full article here.
*Five new autism risk genes include NAV3, ITSN1, MARK2, SCAF1 and HNRNPUL2
In summary: Novel, often hereditary, “moderate-effect” variants linked to autism identified
Article 4: Maternal SMCHD1 regulates Hox gene expression and patterning in the mouse embryo
This study suggests that epigenetic* information, which sits on top of DNA and is normally reset between generations, is more frequently inherited than previously thought. The researchers found a protein, called SMCHD1, in the mother’s egg that regulates the epigenetic inheritance of a set of genes critical for the development of normal body structure in mammals. Epigenetic changes can be influenced by environmental variations such as our diet, but these changes do not alter DNA and are normally not passed from parent to child. This discovery significantly broadens our understanding of which genes have epigenetic information passed from mother to child and which proteins are important for controlling this unusual process. Read the full article here.
*Epigenetics investigates how our genes are switched on and off to allow one set of genetic instructions to create hundreds of different cell types in our body.
In summary: We might inherit more from our parents than we thought, their life experiences may shape us
New in Genetics issue September 2022. Every month, Medicover Genetics curates the most important peer-reviewed scientific publications related to genetics.
References
[1] Rajagopal VM et al. Differences in the genetic architecture of common and rare variants in childhood, persistent and late-diagnosed attention-deficit hyperactivity disorder. Nat Genet. 2022 Aug;54(8):1117-1124. doi: 10.1038/s41588-022-01143-7. Epub 2022 Aug 4. PMID: 35927488. https://www.nature.com/articles/s41588-022-01143-7
[2] Della Valle F et al. LINE-1 RNA causes heterochromatin erosion and is a target for amelioration of senescent phenotypes in progeroid syndromes. Sci Transl Med. 2022 Aug 10;14(657):eabl6057. doi: 10.1126/scitranslmed.abl6057. Epub 2022 Aug 10. PMID: 35947677. https://www.science.org/doi/10.1126/scitranslmed.abl6057
[3] Zhou X et al. Integrating de novo and inherited variants in 42,607 autism cases identifies mutations in new moderate-risk genes. Nat Genet. 2022 Aug 18. doi: 10.1038/s41588-022-01148-2. Epub ahead of print. PMID: 35982159. https://www.nature.com/articles/s41588-022-01148-2
[4] Benetti N et al. Maternal SMCHD1 regulates Hox gene expression and patterning in the mouse embryo. Nat Commun. 2022 Jul 25;13(1):4295. doi: 10.1038/s41467-022-32057-x. PMID: 35879318; PMCID: PMC9314430. https://www.nature.com/articles/s41467-022-32057-x
