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Disease Profile

Popliteal pterygium syndrome

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

PPS; Cleft lip/palate paramedian mucous cysts of the lower lip popliteal pterygium digital and genital anomalies; Faciogenitopopliteal syndrome


Congenital and Genetic Diseases; Ear, Nose, and Throat Diseases; Eye diseases;


Popliteal pterygium syndrome is a condition that affects the development of the face, skin, and genitals. Most people with this disorder are born with a cleft lip and/or a cleft palate. Other symptoms may include depressions (pits) near the center of the lower lip, small mounds of tissue on the lower lip, or missing teeth. Other features may include webs of skin on the backs of the legs across the knee joint (popliteal pterygium), webbing or fusion of the fingers or toes (syndactyly), triangular shaped folds of skin over the nails of the large toes, and tissue connecting the upper and lower eyelids or the upper and lower jaw. Affected people may also have abnormal genitals. There is no growth delay and intelligence is usually normal. Inheritance is autosomal dominant. It is caused by mutations in the IRF6 gene.[1] Treatment may include reconstructive surgery for the oral defects, such as the cleft lip and cleft palate, and for other defects such as the popliteal pterygium or abnormal genitalia.[2]

Popliteal pterygium syndrome is part of the IRF6-related disorders which also include Van der Woude syndrome 2.[3]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Cleft palate
Cleft roof of mouth
Generalized hirsutism
Excessive hairiness over body
Joint stiffness
Stiff joint
Stiff joints

[ more ]

Little lower jaw
Small jaw
Small lower jaw

[ more ]

Thin upper lip vermilion
Thin upper lip
Toe syndactyly
Fused toes
Webbed toes

[ more ]

30%-79% of people have these symptoms
Abnormality of the nail
Abnormality of the ribs
Rib abnormalities
Adhesion of eyelids
Eyelids stuck together

[ more ]

Bifid scrotum
Cleft of scrotum
Undescended testes
Undescended testis

[ more ]

Fibrous syngnathia
Finger syndactyly
Hypoplastic labia majora
Small labia majora
Underdeveloped vaginal lips

[ more ]

Lip pit
Nonketotic hyperglycinemia
Non-midline cleft lip
Popliteal pterygium
Scrotal hypoplasia
Smaller than typical growth of scrotum
5%-29% of people have these symptoms
Ambiguous genitalia
Ambiguous external genitalia
Ambiguous external genitalia at birth
Intersex genitalia

[ more ]

Choanal atresia
Blockage of the rear opening of the nasal cavity
Obstruction of the rear opening of the nasal cavity

[ more ]

Specific learning disability
Split hand
Claw hand
Claw hand deformities
Claw hands
Claw-hand deformities

[ more ]

Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
Cleft upper lip
Cutaneous finger syndactyly
Webbed fingers
Webbed skin of fingers

[ more ]

Dementia, progressive
Progressive dementia

[ more ]

Hypoplasia of the uterus
Small uterus
Underdeveloped uterus

[ more ]

Hypoplasia of the vagina
Underdeveloped vagina
Intercrural pterygium
Lower lip pit
Pyramidal skinfold extending from the base to the top of the nails
Spina bifida occulta
Talipes equinovarus
Club feet
Club foot

[ more ]



Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.


    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • Genetics Home Reference (GHR) contains information on Popliteal pterygium syndrome. This website is maintained by the National Library of Medicine.
      • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Popliteal pterygium syndrome. Click on the link to view a sample search on this topic.


          1. Popliteal pterygium syndrome. Genetics Home Reference. April 2008; https://ghr.nlm.nih.gov/condition/popliteal-pterygium-syndrome.
          2. Ratbi I, Fejjal N, Legendre M, Collot N, Amselem S & Sefiani A. Clinical and molecular findings in a Moroccan patient with popliteal pterygium syndrome: a case report. Journal of Medical Case Reports. 2014; 8:471. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4320515/.
          3. Schutte BC, Saal HM, Goudy S, Leslie E. IRF6-Related Disorders. GeneReviews. July 3, 2014; https://www.ncbi.nlm.nih.gov/books/NBK1407/.