What is Familial Short Stature?
Familial Short Stature (FSS), also known as genetic short stature, is one of the more common causes of short stature; making up between 23–37% of cases. Children with FSS tend to be at the lower extreme of the growth chart and have at least one parent who is also short.
FSS is considered a normal variant of growth and does not tend to impact overall health. Children with FSS usually grow at a normal rate. Final adult height of children with short stature is normally within the range of their parents’ heights.
Hear advice from other parents whose children are also short in stature, compared with others their age. https://morethanheight.com/en/life-with-growth-disorders/advice-for-early-years-parents-of-a-baby-or-toddler-with-a-growth-disorder/
What causes Familial Short Stature?
Familial Short Stature (FSS) is thought to have a genetic cause.
Genetic factors are believed to account for around 80% of variations in full grown adult height. Having one parent with short stature increases the likelihood of any children they have will also be of short stature.
Milder forms of FSS are more likely to arise from the combined effect of multiple genes.
More severe forms of FSS are often caused by a single gene variant that has a major effect on their height.
What are the symptoms of Familial Short Stature?
People with Familial Short Stature (FSS) have a height below the bottom 3% for the corresponding age and sex of the population. Unlike other causes of short stature, growth rate, bone age and onset of puberty are all normal.
If your child is short in stature, keeping track of their growth can help identify if there is a problem early on. Compare your child’s measurements to the national average to see if they are within a healthy range.
Calculate your child’s growth
It is important to keep track of your child’s growth in order to identify if there is a problem early on. We recommend measuring your child every 6 months, which is now easier, with our simple to use growth calculator.
How is Familial Short Stature diagnosed?
A doctor will only give a diagnosis of Familial Short Stature (FSS) when all other causes of short stature have been ruled out. Both parents’ heights are required to confirm a diagnosis of FSS.
Your doctor may carry out blood tests to rule out other causes of your child’s short stature. They will likely recommend monitoring your child’s growth during childhood and adolescence.
Another recommendation your doctor may have is genetic testing to help identify if your child has one of the known mutations associated with FSS, as this may influence decisions regarding treatment.
It is important you speak to your doctor if you have any concerns about your child’s height. Use this helpful guide on what questions to ask and what to expect from your visit. https://morethanheight.com/en/talk-to-your-doctor/visiting-your-paediatrician/
What is the difference between Familial Short Stature and Constitutional Delay of Growth and Puberty?
There is an overlap between Familial Short Stature (FSS) and Constitutional Delay of Growth and Puberty (CDGP); with 17% of people of short stature diagnosed with both. The main difference between the two is that children with FSS will typically have normal growth rate, bone age and onset of puberty. Children with CDGP will often have delayed onset of puberty, atypical growth rate and delayed bone age.
What is the definition of short stature?
Individuals whose body height is below the bottom 3% for the corresponding age and sex of the population are considered to be of short stature. You doctor may plot your child’s height on a graph which shows the national average (or mean) height for their age and sex. If their height is more than 2 standard deviations (SDs) below the mean, they are considered to be of short stature. Standard deviation is a term used in statistics to describe how much a value differs from the mean, or average, value for the group.