There has been increasing discussion on the topic of cats with Down syndrome - or at least cats that appear to have Down syndrome. But can our feline friends actually have this genetic condition?
What is Down syndrome and can cats have it?
Down syndrome, also known as trisomy 21, is a genetic condition that affects humans both physically and intellectually.
Each standard cell in the human body contains two copies of 23 different chromosomes. However, for those with Down syndrome, a third copy - either full or partial - of chromosome 21 is present in each cell. This is known as a trisomy.
Compared to our 23, cats only have 19 pairs of chromosomes. Therefore, as Down syndrome affects chromosome 21, it is physically not possible for the condition to affect cats. There are, however, similar conditions in cats that share some of the same characteristics.
Trisomy in cats
It's rare to come across a cat with a trisomy condition. Often, a kitten born with such a condition will be killed by the mother out of instinct. It may seem cruel, but as an instinctively wild animal, it is her way of maximising the chances of survival for her next generation.
There are different types of feline trisomy conditions, depending on the affected pair of chromosomes. For example, Klinefelter syndrome is a form of trisomy that affects both humans and cats, but only the male sex. Instead of two XY chromosomes present, a third X chromosome is grafted to the pair resulting in XXY. This chromosome abnormality is often the cause of sterility.
Maya and Monty, two beautiful cats with large Instagram followings, are two examples of cats with a form of feline trisomy. Based on their appearance, people often assume that they both have Down syndrome. As shown scientifically, this is not actually the case.
In fact, it's important not to transfer human conditions onto animals on the basis of similar characteristics. In truth, it can be disrespectful to those with the condition, and/or to their families. It can also alter the way we interact and treat animals with various conditions, which should only be done following the advice of the experts - our vets.
Characteristics of feline trisomy
In most cases of feline trisomy, it is relatively apparent that there is something different about the animal. These differences can be physical or intellectual or both. However, they can also differ across conditions.
Common characteristics of feline trisomy include:
- Upturned eyes
- Broad nose
- Small or unusually-shaped ears
- Low or weakened muscle tone
- Walking difficulties or loss of balance
- Heart problems
- Loss of hearing or sight
If you suspect your cat has a trisomy condition, your vet can perform various tests to determine or get closer to a diagnosis.
What causes trisomy?
The cause of trisomy is difficult to isolate. There are countless factors at play, however scientists believe there are some risk factors. For example, the offspring of two cats with the same genetic make-up will have a higher risk of developing defects in utero than those with parents of different genetic structures. Trisomy conditions are therefore more prevalent amongst cats from the same lineage. Mating outside of the family will reduce any risks by about half.
Caring for a cat with a trisomy condition
Basic education and training of a cat with trisomy requires a different amount of support and commitment. As there will often be some behavioral issues, setting boundaries can prove more challenging.
Such cats often require a lot of affection and need to be physically close to their family to feel reassured. Encouraging play and movement is a great way to not only fulfil their play and interaction needs, but also to keep them active. This is especially important when motor and muscle skills are less developed and require more work to help maintain health and functionality. Similarly, poor motor and muscle skills can affect a cat's balance. It’s therefore important to safeguard their environment to avoid any accidental falls.
Similar to human Down syndrome, life expectancy is reduced, and motor skills can become more challenging with age. However, despite a trisomy, a cat with the condition can live a very happy and content life with loving parents.