Diagnosis and Testing
How does someone get tested for Aarskog syndrome?
Genetic testing for Aarskog syndrome is typically ordered by a geneticist and genetic counselor after seeing them for an appointment. A clinic appointment typically involves a complete review of the patient's medical history, a three generation family history that documents health problems and genetic conditions, a detailed physical examination, discussion of recommended testing, and consent for genetic testing if the patient/guardian is interested. Sometimes this happens in one clinic visit, and sometimes this happens over the span of a few clinic visits. Each clinic is different. In terms of insurance, sometimes the clinic checks with your insurance, and sometimes it is your responsibility to call your insurance. As stated earlier, each clinic operates differently. If genetic testing is pursued, a blood sample and signed paperwork is sent to a laboratory that performs the testing. Results are then sent back to the geneticist and genetic counselor who contacts the patient or the patient's guardian with results. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
- Making Sense of Your Genes: A Guide to Genetic Counselling. National Society of Genetic Counselors; Genetic Alliance. Washington (DC): Genetic Alliance; 2008.
More Diagnosis and Testing Content
What clinical features can female carriers of Aarskog syndrome have?
Females who are known carriers of Aarskog syndrome can have mild features of the condition. These may include a widow's peak in their hair or short stature. Some female carriers of Aarskog syndrome do not have any clinical features.
- Orrico A, Galli L, Faivre L, Clayton-Smith J, Azzarello-Burri SM, Hertz JM, Jacquemont S, Taurisano R, Arroyo Carrera I, Tarantino E, Devriendt K, Melis D, Thelle T, Meinhardt U, Sorrentino V. 2010. Aarskog-Scott syndrome: Clinical update and report of nine novel mutations of the FGD1 gene. American Journal of Medical Genetics Part A 152A: 313-318. PubMed ID: 20082460
Do any other genetic conditions look a lot like Aarskog syndrome?
There are other genetic conditions that are similar to Aarskog syndrome. These include Noonan syndrome, Robinow syndrome, SHORT syndrome, and LEOPARD syndrome. All of these conditions are characterized by short stature. Genital differences can be seen in Robinow syndrome and LEOPARD syndrome. There are many differences between Aarskog syndrome and these conditions as well. Heart problems, hearing loss, and bleeding problems can be seen in Noonan syndrome. Freckle-like spots, hearing loss, and heart problems can be seen in LEOPARD syndrome.
How many laboratories in the United States perform genetic testing for Aarskog syndrome?
As of May 2019, genetic testing is available for the FDG1 gene that caused 20% of cases of Aarskog syndrome. As new information is learned about the syndrome, further genes may be identified that cause Aarskog syndrome. The best way to obtain genetic testing is to speak with you doctor or contact a medical geneticist or genetic counselor. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
Is there more than one test for Aarskog syndrome?
As of May 2019, there is only one gene, FGD1, that is currently known to be associated with Aarskog syndrome. Genetic testing involves analyzing this gene for changes. There are two different types of analyses of this gene; these are called sequencing and deletion/duplication. You can imagine the FGD1 gene as a long sentence that provides instruction to the body. Sequencing looks for spelling errors in this sentence. Deletion/duplication involves looking for extra or missing words in this sentence. Spelling errors and extra/missing words can cause the sentence to no longer make sense and therefore no longer provide the proper instruction for the body, causing Aarskog syndrome. Some labs in the United States offer both sequencing and deletion/duplication of the FGD1 gene. Some labs in the United States just offer sequencing or deletion/duplication of the FGD1 gene.
If there is a known FGD1 gene mutation in the family, other family members can easily be tested. However, it will be important to have a copy of the FGD1 gene report in order to pursue testing in other family members. A genetic counselor or medical geneticist can help you coordinate testing in the family. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
Does it matter if you test blood vs. saliva vs biopsy for Aarskog syndrome?
Genetic testing for Aarskog syndrome typically involves using a blood sample. Some laboratories accept saliva samples; it is best to call the lab to see if they accept a saliva sample beforehand. Biopsy is typically not performed for Aarskog syndrome genetic testing.
Who else in my family should I test for Aarskog syndrome?
Genetic testing can be offered for other family members if a FGD1 gene change is identified in an affected person. Testing can be offered to other people depending on who is diagnosed first. A few examples are the following:
- If a male child is found to have FGD1 gene mutation on the X-chromosome, carrier testing can be offered to the mother. The child's father would not be offered testing because father does not pass on his X chromosome to his male children (Aarskog syndrome is most frequently an X-linked condition). If mother is found to be a carrier, her siblings can be offered testing.
- If female child is found to have a FGD1 gene mutation, carrier testing can be offered to both her mother and father. If either mother or father are affected, their siblings can be offered testing.
Each family's situation is different, and it is beneficial to meet with a geneticist and genetic counselor to discuss risks to other family members and who testing is appropriate for. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.
If a mother is a carrier of Aarskog syndrome, is there testing that can be performed during the pregnancy to see if her baby is affected?
If a mother is a known carrier of or affected by Aarskog syndrome and has a known FGD1 gene mutation, genetic testing can be performed during the pregnancy. Chorionic villus sampling (CVS) and amniocentesis are both available. CVS involves removing a piece of the placenta and sending the sample to a laboratory for genetic testing. CVS can be performed around 10-12 weeks of gestation. Amniocentesis involves taking a sample of amniotic fluid and sending it to the laboratory for genetic testing. This testing can be performed starting at 15 weeks of gestation. Testing involves looking for the specific FGD1 gene mutation found in the mother. To note, clinical features cannot be predicted before birth. Because both CVS and amniocentesis are invasive, there is a small risk for miscarriage. If one is interested in this prenatal diagnostic testing, they can speak with a reproductive genetic counselor in their area. Genetic counselors can be found on the National Society of Genetic Counselors website.
Is there newborn testing for Aarskog syndrome?
Each state has a newborn screen which includes a group of genetic conditions. Aarskog syndrome is not included in any newborn screens in the United States. If there is a family history of Aarskog syndrome or if Aarskog syndrome is suspected at birth, genetic testing can be performed using cord blood or another blood sample. Contacting a genetic counselor or medical geneticist before the baby is born will be helpful to find out how best to coordinate testing at birth in your area. A medical geneticists can be found by asking your doctor for a referral or looking on the American College of Medical Geneticists website. Genetic counselors can be found on the National Society of Genetic Counselors website.