What is Kniest dysplasia?
Kniest dysplasia is a disorder of bone growth characterized by short stature (dwarfism) with other skeletal abnormalities and problems with vision and hearing.
People with Kniest dysplasia are born with a short trunk and shortened arms and legs. Adult height ranges from 42 inches to 58 inches. Affected individuals have abnormally large joints that can cause pain and restrict movement, limiting physical activity. These joint problems can also lead to arthritis. Other skeletal features may include a rounded upper back that also curves to the side (kyphoscoliosis), severely flattened bones of the spine (platyspondyly), dumbbell-shaped bones in the arms and legs, long and knobby fingers, and an inward- and upward-turning foot (clubfoot).
Individuals with Kniest dysplasia have a round, flat face with bulging and wide-set eyes. Some affected infants are born with an opening in the roof of the mouth called a cleft palate. Infants may also have breathing problems due to weakness of the windpipe. Severe nearsightedness (myopia) and other eye problems are common in Kniest dysplasia. Some eye problems, such as tearing of the back lining of the eye (retinal detachment), can lead to blindness. Hearing loss resulting from recurrent ear infections is also possible.
How common is Kniest dysplasia?
Kniest dysplasia is a rare condition; the exact incidence is unknown.
What genes are related to Kniest dysplasia?
Kniest dysplasia is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in the clear gel that fills the eyeball (the vitreous) and in cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Type II collagen is essential for the normal development of bones and other connective tissues that form the body's supportive framework.
Most mutations in the COL2A1 gene that cause Kniest dysplasia interfere with the assembly of type II collagen molecules. Abnormal collagen prevents bones and other connective tissues from developing properly, which leads to the signs and symptoms of Kniest dysplasia.
Read more about the COL2A1 gene.
How do people inherit Kniest dysplasia?
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
Most cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
Here is the other thing they think she may have....
What is spondyloperipheral dysplasia?
Spondyloperipheral dysplasia is a disorder that impairs bone growth. This condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly), with the exception of the great toes. Other skeletal abnormalities associated with spondyloperipheral dysplasia include short stature, shortened long bones of the arms and legs, exaggerated curvature of the lower back (lordosis), and an inward- and upward-turning foot (clubfoot). Additionally, some affected individuals have nearsightedness (myopia), hearing loss, and intellectual disability.
How common is spondyloperipheral dysplasia?
This condition is rare; only a few affected individuals have been reported worldwide.
What genes are related to spondyloperipheral dysplasia?
Spondyloperipheral dysplasia is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in the clear gel that fills the eyeball (the vitreous) and in cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Type II collagen is essential for the normal development of bones and other connective tissues that form the body's supportive framework.
Mutations in the COL2A1 gene interfere with the assembly of type II collagen molecules, reducing the amount of this type of collagen in the body. Instead of forming collagen molecules, the abnormal COL2A1 protein builds up in cartilage cells (chondrocytes). These changes disrupt the normal development of bones and other connective tissues, leading to the signs and symptoms of spondyloperipheral dysplasia.
Read more about the COL2A1 gene.
How do people inherit spondyloperipheral dysplasia?
This condition is probably inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
Our Angle With Out Wings XoXo
- All you need is L.O.V.E
- Hey! Im Ashley and I live in the Washington area. God has blessed me with three beautiful children. One of my children has a rare form of dwarfism. We are still waiting on a dignosis, which can take up to a year. So while i patiently wait ive been doing a TON of research on could it be this or oh what if she has that...I have this blog to have others find me and as well helping others who may be experiencing the same issue's or have already been there. Enjoy to read or even chat & of course enjoy our wonderful journey that God has planed for us :D
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Hi! My name is Taryn and I just came across your blog! Your sweet girl is precious, and hang in there! Our son wasn't officially diagnosed until he was 2 years old. What hospital are you guys going to? We are in Texas and see a geneticist at Texas Children's Hospital's Skeletal Dysplasia Clinic. The geneticist we saw in Florida was a general geneticist and had a hard time even considering other types than Achon and Hypochon. Jr is diagnosed as SEDc/Kniest. He falls under 'type 2 collagen disorders' but because it is a random gene mutation, and he only shows symptoms at the growth plates, they are having a hard time diagnosing it 100%. Just keep your head up and never let this stop your daughter in anything! Jr is 6 and will tell other kids his age 'I know it's odd that I am so short, but it's ok, I am your age and we can still play together! I just have a type of dwarfism' His infamous quote is 'even a little guy can make a biiiig difference'. You will always have questions, and you will always seek more info. Unfortunately, when it is random gene mutation, no case will ever be textbook! Just remember God blessed you with her for a reason, and she will teach you more than you will ever know! God bless you and your family along this journey!!
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