KSG Information & Support

Kniest, Spondylometaphyseal Dysplasia, Spondyloepimetaphyseal dysplasia and related conditions, info & support group.

A group of about 30 people at a with Kniest, SED and SMD.

Welcome to the updated KSG website!

This website was originally started in 1999 by a psychologist and a statistician. As the years have gone by and the world wide web has change, our website is changing, too!

The new website focuses on living with Kniest, SED and SMD: learning about the conditions, managing medical issues and advocacy work. We hope to bring new people of short stature and their families into the Little People of America community as well as help individuals get the medical care they need. We work with medical providers help them research these rare conditions and foster appropriate research. We also work to fight ablesim.

Disclaimer: the information on this website is for informational purposes only and no medical decisions should be based on its contents.

We hope you will find what you need on the Kniest SED Web Site. If not please contact us by emailing ksginfo{at}gmail.com. Any and all questions are welcomed!


Diagnoses are made based off X-Rays, blood tests, symptoms, and sometimes genetic tests. Not all types of Kniest, SED and SMD have a genetic test yet.

Some types of dwarfism are better understood than others. A geneticist can usually provide a specific diagnosis for dwarfing conditions or skeletal dysplasias. Skeletal dysplasias are a complex group of conditions. Medical providers are learning more and more about these complex diagnoses all the time! It’s is possible for an individual’s diagnosis to be modified or changed to more accurately describe the condition. However, a change in the name of the diagnosis usually does not change an individual’s prognosis (what is expected to happen with the condition).

Just as sisters and brothers look different, people wit the same diagnosis can look very different. People with SEDC can be very short, or shorter than average. Every case is different. People with the same kind of dwarfism can look quite different and have different physical symptoms.

Genetic changes or mutations happen randomly. Nothing you did contributed in any way to this condition.

Intelligence is usually not affected. People born with SED, SMD, and Kniest usually have normal intelligence.

It is hard to tell how tall your child will be? Some people with SMD-K will be between 4 and 5 feet. We know of people with Kniest who are average sized, though this is very rare.

People with SED-C range between 3 and 5 feet.

There is a lot of variation among people with the same diagnosis. Growth hormones are not likely to add much height to either of these conditions, as the levels of growth hormones are normal and cells are reacting to them appropriately.

There may be. It is important to learn as much as possible about the condition and establish a good relationship with your family physician and a skeletal dysplasia clinic. Some potential complications, such as retinal detachment and back problems, can be prevented if caught in time. Work with your medical team to know which symptoms to look out for. Also, feel free to reach out to families in our “meet people with Kniest, SED and SMD’ section.

Your child’s primary care physician needs to be in touch with someone who specializes in skeletal dysplasias dwarfism). If a medical provider claims to have seen many cases like yours, ask how many. These conditions are very rare. It is vital to contact a well-known skeletal dysplasia center for guidance and direction in your child’s care. A little bit of knowledge can be very dangerous. 

You can contact Little People of America (LPA) http://www.lpaonline.org, or see the skeletal dysplasia clinic list to set up an appointment at a skeletal dysplasia clinic where you will be seen by medical professionals are very experienced with skeletal dysplasias. Insurance companies frequently pay for such out-of-plan visits to these clinics since SED and SMD and Kniest are rare conditions.

You may need to make some important medical decisions with your doctor. It is vital you are well informed about potential complications and treatments. Reach out for families with Kniest, SED and SMD to get support for these decisions.

It is hard to keep a child from being active, but try and get your child to do less dangerous activities. For example, bike riding is fine, but off road mountain biking should be discouraged. Jumping on trampolines is dangerous for all users and should not be done by people with Spondyloepiphyseal Dysplasia or Spondylometaphyseal Dysplasia or Kniest dysplasia.

Doses of all medication should be based on WEIGHT, not height or age. People with disproportionate dwarfism do not fit in any height and weight charts designed for average-statured people.

Due to potential neck complications, the neck should be carefully supported during all anesthesia procedures. Neck stability and lung capacity should be evaluated by experienced medical providers BEFORE anesthesia is performed.

Yes. There are many wonderful books to help your family and friends learn about dwarfism! Please visit our books and movies section: https://ksginfo.org/our-stories/ .