Mutations subtypes

EHLERS DANLOS SYNDROME

is not a single condition but a group of 13 different inherited connective tissue disorders, each with its own unique genetic basis and characteristics.

The chart you see below, provides an overview of the different EDS subtypes, their associated genetic mutations, and the proteins involved in their development.

These genetic variations lead to a range of symptoms, from joint hypermobility and fragile skin to life-threatening vascular complications, depending on the subtype.

Inheritance Patterns

Autosomal Dominant and Autosomal Recessive

The two key patterns of how traits get passed from parents to children.

Autosomal refers to the 22 pairs of non-sex chromosomes that everyone has. Since these genes aren’t on the X or Y chromosomes, both males and females are equally likely to inherit the trait or condition.

Autosomal Dominant Inheritance

In autosomal dominant inheritance, you only need one copy of a mutated gene to show the trait or condition. This means that if one parent has the mutation, they can pass it on, even if the other parent doesn’t.

How it works: Each child has a 50% chance of inheriting the condition if one parent has the mutation.

Examples: Conditions like Huntington’s disease, Marfan syndrome, and some types of familial hypercholesterolemia follow this pattern.

Because only one mutated gene is enough, these conditions tend to appear in every generation, it doesn’t usually skip generations.

The specific gene responsible hasn’t been identified yet, but it tends to run in families.

Classical EDS (cEDS), Caused by mutations in the COL5A1 or COL5A2 genes.

Vascular EDS (vEDS):Linked to mutations in the COL3A1 gene, and requires immediate medical attention due to the risk of organ rupture.

Autosomal Recessive Inheritance

With autosomal recessive inheritance, things are a bit different. These types are rare and need two copies of the mutated gene. One from each parent for the condition to appear. If a person only has one mutated gene, they are called a carrier but won’t show any symptoms.

How it works: If both parents are carriers, each child has: 25% chance of inheriting both mutated copies (and having the condition), 50% chance of inheriting one mutated copy (becoming a carrier), and 25% chance of inheriting two normal copies (no condition, not a carrier).

Examples: Conditions like cystic fibrosis, sickle cell anemia, and Tay-Sachs disease follow this pattern.

These conditions can skip generations because they only appear when two carriers have children who both pass on the mutated gene. These types can make it difficult to spot in family histories until two carriers have a child with the condition.

So, here’s the quick breakdown.

- Autosomal Dominant: Only one mutated gene is needed, and the condition is often seen in every generation.

- Autosomal Recessive: Two mutated genes are needed, and the condition can skip generations since carriers don’t show symptoms.

Understanding these inheritance patterns helps explain why some traits appear more often in families than others and why genetic testing is so important, especially if there’s a family history of certain conditions.

Recessive EDS Types

Kyphoscoliotic EDS (kEDS)

Characterized by severe scoliosis, muscle weakness, and eye problems.

Linked to mutations in the PLOD1 gene.

Dermatosparaxis EDS (dEDS): Causes extremely fragile, saggy skin and poor wound healing. Caused by mutations in the ADAMTS2 gene.

This happens when your DNA changes randomly during development, before you’re even born. It’s like a typo in your genetic blueprint. One that rewrites the way your body creates connective tissue.

Scientists don’t always know why spontaneous mutations occur. They can happen by chance. Like a small mistake during the formation of egg or sperm cells, or even during early fetal development. Environmental factors may play a role, but a lot of the time, it’s just nature doing its thing, and the result is that you’re the first in your family with EDS.

Discovering that you have EDS when no one else in your family does can be overwhelming. You might feel confused, like, ‘How did this even happen? Or find it hard to get doctors to take you seriously. But spontaneous mutations are a real and documented cause of genetic conditions like EDS, and it’s not uncommon for people to become the first in their family with it.

Getting diagnosed without a family history can make the journey longer. Doctors might assume, ‘There’s no family history, so it can’t be genetic,’ delaying diagnosis. But the reality is, spontaneous mutations in conditions like Classical EDS (cEDS) or Hypermobile EDS (hEDS) are more common than you think. That’s why genetic testing can be so important.

So, if you’ve been told, ‘There’s no way you have EDS without a family history, now you know that’s not true. Whether EDS runs in your family or you’re the first with a spontaneous mutation, your diagnosis is real, and your journey matters.

Mosaicism in Ehlers-Danlos Syndrome

Mosaicism means that different groups of cells in your body have different DNA, even though you’re technically one person. It’s like your cells have multiple blueprints. Some cells carry mutations that cause issues, while others don’t.

Since EDS is connected to collagen mutations, having mosaicism means that only some parts of your body may be affected. This could explain why symptoms are so inconsistent between people and even within the same person!

For example, one area might have weaker joints or fragile skin, while other tissues function normally because they don’t carry the mutation. That’s the ‘hidden twist’ with mosaicism! Mosaicism might also be why some family members with the same EDS gene have different severities of symptoms or why it can take so long to get diagnosed.

Mosaicism makes it harder to detect mutations through traditional genetic testing, because not every cell has the same genetic change. Some mutations might only show up in certain tissues, making diagnosis tricky, especially for rare or newly discovered types of EDS. So, if you’ve ever felt like EDS is hard to pin down, mosaicism might be part of the reason! It’s a reminder that our bodies are way more complicated than they seem.

The Many Faces of ehlers danlos syndrome

EHLERS DANLOS SYNDROME

Genetic Variations

Inheritance Patterns

Autosomal Dominant and Autosomal Recessive

Recessive EDS Types

Spontaneous Mutation

Mosaicism in Ehlers-Danlos Syndrome

The Many Faces of ehlers danlos syndrome

EHLERS DANLOS SYNDROME

Genetic Variations

Inheritance Patterns

Autosomal Dominant and Autosomal Recessive

Recessive EDS Types

Spontaneous Mutation

Mosaicism in Ehlers-Danlos Syndrome

This website uses cookies.