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Genetic and Rare Diseases Information Center (GARD)

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TARP syndrome


Other Names for this Disease

  • Pierre Robin syndrome with congenital heart malformation and clubfoot
  • Talipes equinovarus, atrial septal defect, robin sequence, and persistence of left superior vena cava
  • TARPS
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

My 1 year old son and 21 year old brother were recently diagnosed with TARP syndrome. My mother and I have tried to find information on it, but with how rare it is, it is very difficult to find much. So far I have found a little information on one other living boy with TARP. I am just trying to find more information on this syndrome so maybe I will know more about my son and his condition.

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is TARP syndrome?

TARP syndrome is a rare condition affecting males that causes several birth defects. TARP stands for Talipes equinovarus, Atrial septal defect, Robin sequence, and Persistent left superior vena cava. Those with TARP syndrome have clubfoot deformity (talipes equinovarus) and congenital heart defects involving failure of the upper heart chambers to close (atrial septal defect). The Robin sequence (also known as Pierre Robin’s sequence) is characterized by a small lower jaw at birth that prevents proper feeding of the infant, followed by a retracted or displaced tongue. A high-arched, cleft soft palate is also commonly seen.[1] Affected individuals also have persistent left superior vena cava. TARP syndrome has been reported to cause death before birth or soon after birth. This condition is caused by mutations in the RBM10 gene and is inherited in an X-linked recessive fashion.[2]
Last updated: 12/9/2013

What are the signs and symptoms of TARP syndrome?

TARP is an acronym for the 4 main features that were present in individuals originally diagnosed with TARP syndrome: More recently, some affected individuals (confirmed by genetic testing) have been described having a more diverse range of signs and symptoms. Two boys from one family with TARP syndrome were born without clubfoot, but had additional features including polydactyly (additional fingers and/or toes); cutaneous syndactyly (webbing of the skin between the fingers and/or toes); and masses on the underside of the tongue (sublingual tongue masses). An individual in another family had only one of the 4 main features. An individual in a third family had only 2 of the 4 features of TARP.[3]

Additional abnormalities that have been reported in the medical literature in affected individuals include failure to thrive; abnormal skull shape; round face; short palpebral fissures (decreased width of each eye); small or abnormally-shaped ears; poor muscle tone (hypotonia); developmental delay; eye or visual abnormalities; hearing loss; airway or lung abnormalities; undescended testicles (cryptorchidism); structural brain abnormalities; and intellectual disability.[3][4]

Most affected males have died before birth or shortly after birth. However, in 2011 there was a report of an affected individual who was 3 years, 7 months old and was surviving with intensive medical care. The authors of this report concluded that long-term survival is possible for individuals with TARP syndrome and that older affected individuals may exist.[4]
Last updated: 12/5/2013

What causes TARP syndrome?

TARP syndrome is a genetic condition caused by mutations in the RBM10 gene, which is located on the X chromosome. There is little information available about how mutations in this gene specifically cause TARP syndrome. However, in 2010 researchers showed that the RBM10 gene is expressed in mouse embryos in the branchial arches (embryonic structures that give rise to parts of the head and neck) and limbs, which is consistent with body parts known to be affected in individuals with TARP syndrome. The signs and symptoms of TARP syndrome occur when this gene does not function correctly.[5]
Last updated: 12/6/2013

How is TARP syndrome inherited?

TARP syndrome is inherited in an X-linked recessive manner. This means that the mutated gene responsible for TARP syndrome (RBM10) is located on the X chromosome, and typically only affects males. Males have one X chromosome and one Y chromosome, while females have two X chromosomes. If a female has one mutated copy of RBM10 and one normal copy, she would typically be an unaffected carrier of this condition. Occasionally, female carriers of an X-linked recessive condition may have varying degrees of signs or symptoms of the condition; this is due to differences in X chromosome inactivation.

When a female carrier of an X-linked condition has children, each daughter has a 50% (1 in 2) risk to also be a carrier, and a 50% risk to not be a carrier (and have 2 normal copies of the gene). Each son has a 50% risk to be affected and a 50% risk to be unaffected.
Last updated: 12/9/2013

Is genetic testing available for TARP syndrome?

Yes, genetic testing (including carrier testing) is available for TARP syndrome. The Genetic Testing Registry (GTR) provides information about the labs that offer genetic testing for this condition. On the GTR Web site, click on the title "Test for TARP syndrome" to find out more information about each test. The intended audience for the GTR is health care providers and researchers. Therefore, patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Last updated: 12/6/2013

How can I find a genetics professional in my area?

Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about genetic consultations is available from Genetics Home Reference. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.

The following online resources can help you find a genetics professional in your community:
Last updated: 6/5/2014

References
  • Campbell, RM. Femoral Hypoplasia-Unusual Facies Syndrome, NORD Guide to Rare Disorders. Philadelphia: Lippincott Williams & Wilkins; 2003;
  • Johnston JJ, Teer JK, Cherukuri PF, Hansen NF, Loftus SK; NIH Intramural Sequencing Center (NISC), Chong K, Mullikin JC, Biesecker LG. Massively parallel sequencing of exons on the X chromosome identifies RBM10 as the gene that causes a syndromic form of cleft palate. Am J Hum Genet. 2010; 86(5):743-748. http://www.ncbi.nlm.nih.gov/pubmed/20451169. Accessed 5/6/2011.
  • Johnston JJ. et. al. Expansion of the TARP syndrome phenotype associated with de novo mutations and mosaicism. Am J Med Genet A. November 20, 2013; Epub ahead of print:Accessed 12/5/2013.
  • Gripp KW, Hopkins E, Johnston JJ, Krause C, Dobyns WB, Biesecker LG. Long-term survival in TARP syndrome and confirmation of RBM10 as the disease-causing gene. Am J Med Genet A. October 2011; 155A(10):2516-2520. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3183328/. Accessed 12/5/2013.
  • Marla J. F. O'Neill. TARP syndrome; TARPS. OMIM. June 21, 2010; http://omim.org/entry/311900. Accessed 12/6/2013.
Other Names for this Disease
  • Pierre Robin syndrome with congenital heart malformation and clubfoot
  • Talipes equinovarus, atrial septal defect, robin sequence, and persistence of left superior vena cava
  • TARPS
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.