Spondyloepimetaphyseal dysplasia Matrilin-3 related (SEMD, MATN3-related) is a very rare condition that begins before or just after birth. SEMD, MATN3-related causes bone growth and development problems. Someone with SEMD, MATN3-related will have early-onset disproportionate dwarfism. This means that they will be shorter than most other people. They will also have body parts that are too large or small compared to their body size. These symptoms will appear early in life.
SEMD, MATN3-related will cause the bones of the legs to be curved (bowed). Someone with SEMD, MATN3-related will have growth problems in their femurs, pelvis, and spine. The femurs, pelvis, and spine are all bones in the body. The femur is the large bone in the thigh. The pelvis is the bone that makes up the hips. The spine is the series of bones that runs down a person’s back. The vertebrae are the bones that make up the spine. SEMD, MATN3-related will cause the vertebrae to be flat. Someone with SEMD, MATN3-related will have lordosis (swayback). This is a lower back that is too curved.
SEMD, MATN3-related is passed down from parents to their children through genes. Genes act as an instruction manual for the body. Genes are made up of DNA. DNA is a “code” made up of small parts called nucleotides. A gene mutation is when one or more nucleotides in the DNA “code” that makes up a gene is changed. SEMD, MATN3-related is caused by a mutation in the MATN3 gene. SEMD, MATN3-related is inherited in an autosomal recessive pattern. This means that both parents pass a mutation in the MATN3 gene down to the child in order for the child to have SEMD, MATN3-related.
If you or a family member has been diagnosed with SEMD, MATN3-related, talk to your doctor about the most current treatment options. Support groups are also good sources of support and information.