Author: Catherine

Researchers have studied different aspects of PCOS, including its genetic, hormonal, and environmental factors, to understand it better. The genetic basis of PCOS was first reported by Cooper and colleagues in 1968, who found that PCOS often runs in families. This suggested it might be inherited in an autosomal dominant pattern, meaning that having just one copy of the affected gene could increase the risk of developing such a condition. 

Twin studies have been helpful with identical (monozygotic) and fraternal (dizygotic) twins showing that PCOS has a strong genetic component. The heritability of PCOS, which is the proportion of the risk that is genetic, is observed to be about 72%. 

Additionally, studies of families have found that 55-60% of first-degree relatives (like sisters or daughters) of someone with PCOS also have the condition. This means that genetics play a big role in whether someone develops PCOS. However, because many genes and environmental factors contribute to PCOS, the exact genetic basis may differ between and within families. This complexity means that while genetics play a significant role, other factors are also important.

Increased Uric Acid Levels:  This condition referred to as hyperuricemia is a main trigger for gout as it can lead to the formation of urate crystals in the joints.  

Impaired Excretion Pathways: This condition is a result of factors such as kidney disease or certain medications that interfere with uric acid excretion. As a result, the accumulated uric acid crystallizes in the joints, triggering inflammation and pain. 

Genetic Factors: Genetic factors are crucial in gout, specifically those affecting how the body handles uric acid. Studies have shown that 65% of gout cases are inherited or run in the family. Recognizing genetic influences like identifying family medical history along with lifestyle modification will help individuals at higher risk.

Diet and Lifestyle Factors: High purine foods (e.g. crustaceans, red and organ meats, oily fishes) and alcohol or sugary beverages are the most common causes of the spike in uric acid levels. What you do daily and what you give your body is essential in treating gout as it could help lower uric acid levels and reduce strain on the joints, therefore preventing gout flare-ups. 

Understanding how cleft chins are inherited involves the complexity of genetics as researchers like John H. McDonald of the University of Delaware concluded. We now know that each individual inherits two copies of every gene, one from a mother and one from a father. Variation in genes is presented by different versions known as alleles. In the case of cleft chins, when simplified, there are at least two alleles: one for a cleft chin and one for a smooth chin. The cleft chin allele is dominant, meaning it usually manifests itself even if only one copy is inherited, while the smooth chin allele is recessive and requires two copies to be expressed.

So, if an individual has a cleft chin, they may have inherited two dominant alleles or one dominant and one recessive allele. This genetic combination influences the likelihood of passing the cleft chin trait to their offspring. Family studies have shown that even parents with smooth chins can have children with cleft chins, indicating the complexity of the actual inheritance patterns.

While early genetic theories suggested that a single dominant gene controlled cleft chin inheritance, recent research by Bhanu and Malhotra has revealed a more nuanced picture. Their studies demonstrated significant variation in cleft chin occurrence among different populations and genders, with factors like age also playing a role. Furthermore, John H. McDonald’s research at the University of Delaware debunked the idea of a simple dominant-recessive trait, highlighting the involvement of multiple genes and environmental factors such as aging in shaping the chin. 

Instead of a simple dominant model, many genes work together to determine chin shape, resulting in a wide range of chin types. For example, in early studies, Guenther (1939) found 9 cases in 5 generations, and von Meirowsky (1924) reported 25 cases in 4 generations. Gorlin (1982) noted it in 4 generations, and McKusick (1988) found it in 3 generations. McKusick (1992) stated that a publishing colleague of his, who had this trait, was in the third generation of affected males in his family. In general, females appear to be less conspicuously affected than males. Family studies have shown that having a cleft chin is not just about having strong “cleft”  alleles—sometimes even parents with smooth chins have kids with cleft chins.

Research by Bhanu and Malhotra (1972), shows that there’s significant variation in the occurrence of cleft chins among different groups and genders. For example, the data showed that 4% to 71% of Indian populations had cleft chins and that German males possessed them with greater frequency than their female counterparts. Moreover, they discovered that as age progresses, so does the likelihood of a cleft chin becoming more prominent. This, therefore shows the intricate nature of cleft chin inheritance, its appearance, and the need for a comprehensive understanding of genetic and environmental influences on facial traits.