About Trichorhinophalangeal Syndrome Type 2
The New York Center for Rare Diseases supports the mission and guidelines of the Genetic and Rare Diseases Information Center (GARD). The following information is provided by the NIH.
Summary
Trichorhinophalangeal syndrome type 2 (TRPS2), also known as Langer-Giedion syndrome, is an extremely rare inherited multisystem disorder. The condition is characterized by intellectual deficit and numerous other abnormalities including excess folds of skin, multiple bony growths (exostoses), characteristic facial features, and cone-shaped phalangeal epiphyses (the growing ends of the bones in the fingers). The range and severity of symptoms varies greatly from person to person. TRPS2 is transmitted in an autosomal dominant manner, but many sporadic cases have been reported. TRPS2 is due to the absence of genetic material (chromosomal deletions) on chromosome 8, which often includes the TRPS1 gene and EXT1 gene. The size of the deletion varies from person to person.
Causes
What Causes This Disease?
Genetic Mutations: Trichorhinophalangeal syndrome type 2 is caused by genetic mutations, also known as pathogenic variants. Genetic mutations can be hereditary, when parents pass them down to their children, or they may occur randomly when cells are dividing. Genetic mutations may also result from contracted viruses, environmental factors, such as UV radiation from sunlight exposure, or a combination of any of these.
If you suspect you may have this disease, you may want to start collecting your family health history. Information such as other family members who have had similar symptoms, when their/your symptoms first appeared, or exposures to any potential disease-causing environmental factors should be discussed with your medical team.
Chromosomal Changes: Trichorhinophalangeal syndrome type 2 is caused by a change in the number of chromosomes a person has, or a change in their structure. Chromosomes are structures within cells that hold all our genes. People usually have 46 chromosomes, 23 come from the biological mother and 23 come from the biological father. Most of the time, chromosomal changes occur randomly in the sperm or egg, but some changes are known to be passed on from parent to child.
Given the known chromosomal changes for this disease, you may want to ask your health care team if chromosome testing is right for you. Results from chromosome testing can confirm or rule out a suspected chromosomal disease or help determine a person’s chance of passing on a disease.
Can This Disease Be Passed Down From Parent to Child?
Yes. It is possible for a biological parent to pass down genetic mutations that cause or increase the chances of getting this disease to their child. This is known as inheritance. Knowing whether other family members have previously had this disease, also known as family health history, can be very important information for your medical team.
There are multiple ways, or patterns, a disease can be inherited depending on the gene(s) involved. Based on GARD’s current data, this disease can be inherited in the following pattern(s):
Autosomal Dominant: Autosomal means the gene involved is located on one of the numbered chromosomes. Dominant means that a child only needs to inherit one copy of the mutated gene, from either biological parent, to be affected by the disease.
People affected by an autosomal dominant disease have a 50% chance of passing on the mutated gene to their biological child.