National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Genitopatellar syndrome



Other Names:
Absent patellae, scrotal hypoplasia, renal anomalies, facial dysmorphism, and mental retardation; GTPTS; Absent patellae-scrotal hypoplasia-renal anomalies-facial dysmorphism-intellectual disability syndrome
Categories:

Genitopatellar syndome (GPS) is a genetic condition which affects different parts of the body. The most common signs and symptoms (features) of GPS include abnormal genitals (for boys, undescended testicles and underdeveloped scrotum; for girls, small labia and large clitoris), missing or underdeveloped kneecaps (patellae), stiff large joints with limited movement (such as contractures of hips and knees or clubfoot), developmental delay, and intellectual disabilities. Other features may include missing the structure that connects the two sides of the brain (agenesis of the corpus callosum), swelling of the kidney due to build up of urine (hydronephrosis) and congenital heart defects (the baby's heart did not form normally). Thyroid problems have been reported in some cases.[1][2]

Genitopatellar syndrome (GPS) is caused by changes or mutations in the KAT6B gene..[1][2][3] Diagnosis of GPS is usually suspected by the signs and symptoms (features) seen in the child. It is confirmed by genetic testing. There is no cure for GPS. Treatment focuses on the features present in each child and may include surgery (for example to correct heart defects or clubfoot), speech therapy, physical therapy (to increase range of motion of joints), and early childhood intervention and special education programs (for developmental delays and intellectual disability).[3]

As of 2016, medical researchers are trying to decide if genitopatellar syndrome (GPS) is a separate syndrome from Say–Barber–Biesecker–Young–Simpson syndrome (SBBYSS). Both syndromes are caused by changes (mutations) in the same gene (KAT6B). The two syndromes also share a lot of the same features, and some children with mutations in KAT6B gene have a combination of features that fall in between the GPS and SBBYSS. This suggests that GPS and SBBYSS may be two ends of a spectrum of the same syndrome..[1][2]
Last updated: 1/10/2017

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.

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Medical Terms Other Names
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HPO ID
80%-99% of people have these symptoms
Arthrogryposis multiplex congenita 0002804
Clitoral hypertrophy
Enlarged clitoris
0008665
Coarse facial features
Coarse facial appearance
0000280
Cryptorchidism
Undescended testes
Undescended testis
[ more ]
0000028
Global developmental delay 0001263
Hip contracture 0003273
Hydronephrosis 0000126
Hypoplastic ilia 0000946
Hypoplastic ischia 0003175
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ]
0001249
Knee flexion contracture 0006380
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ]
0000252
Multicystic kidney dysplasia 0000003
Patellar aplasia
Absent kneecap
0006443
Prominent nasal bridge
Elevated nasal bridge
High nasal bridge
Prominent bridge of nose
Prominent nasal root
Protruding bridge of nose
Protruding nasal bridge
[ more ]
0000426
Prominent nose
Big nose
Disproportionately large nose
Increased nasal size
Increased size of nose
Large nose
Pronounced nose
[ more ]
0000448
Scrotal hypoplasia
Smaller than typical growth of scrotum
0000046
Short palm 0004279
Wide nose
Broad nose
Increased breadth of nose
Increased nasal breadth
Increased nasal width
Increased width of nose
[ more ]
0000445
30%-79% of people have these symptoms
Agenesis of corpus callosum 0001274
Delayed eruption of teeth
Delayed eruption
Delayed teeth eruption
Delayed tooth eruption
Eruption, delayed
Late eruption of teeth
Late tooth eruption
[ more ]
0000684
Delayed speech and language development
Deficiency of speech development
Delayed language development
Delayed speech
Delayed speech acquisition
Delayed speech development
Impaired speech and language development
Impaired speech development
Language delay
Language delayed
Language development deficit
Late-onset speech development
Poor language development
Speech and language delay
Speech and language difficulties
Speech delay
[ more ]
0000750
Fine hair
Fine hair shaft
Fine hair texture
Thin hair shaft
Thin hair texture
[ more ]
0002213
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ]
0000316
Long philtrum 0000343
Low-set ears
Low set ears
Lowset ears
[ more ]
0000369
Micrognathia
Little lower jaw
Small jaw
Small lower jaw
[ more ]
0000347
Seizure 0001250
Sparse scalp hair
Reduced/lack of hair on scalp
Scalp hair, thinning
Sparse, thin scalp hair
sparse-absent scalp hair
[ more ]
0002209
Talipes equinovarus
Club feet
Club foot
Clubfeet
Clubfoot
[ more ]
0001762
5%-29% of people have these symptoms
Apnea 0002104
Atrial septal defect
An opening in the wall separating the top two chambers of the heart
Hole in heart wall separating two upper heart chambers
[ more ]
0001631
Feeding difficulties
Feeding problems
Poor feeding
[ more ]
0011968
Gastroesophageal reflux
Acid reflux
Acid reflux disease
Heartburn
[ more ]
0002020
Hearing impairment
Deafness
Hearing defect
[ more ]
0000365
Pulmonary hypoplasia
Small lung
Underdeveloped lung
[ more ]
0002089
Radioulnar synostosis
Fused forearm bones
0002974
Short stature
Decreased body height
Small stature
[ more ]
0004322
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Autosomal recessive inheritance 0000007
Brachydactyly
Short fingers or toes
0001156
Colpocephaly 0030048
Congenital hip dislocation
Dislocated hip since birth
0001374
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty
[ more ]
0002015
Enlarged labia minora 0008683
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ]
0001290
Hypoplastic inferior pubic rami 0008823
Intellectual disability, progressive
Mental retardation, progressive
Progressive mental retardation
[ more ]
0006887
Laryngomalacia
Softening of voice box tissue
0001601
Micropenis
Short penis
Small penis
[ more ]
0000054
Muscular hypotonia
Low or weak muscle tone
0001252
Patellar dislocation
Dislocated kneecap
0002999
Periventricular heterotopia 0007165
Polyhydramnios
High levels of amniotic fluid
0001561
Psychomotor retardation 0025356
Short phalanx of finger
Short finger bones
0009803
Ventricular septal defect
Hole in heart wall separating two lower heart chambers
0001629
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Last updated: 7/1/2020

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.

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

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 Genitopatellar syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. Radvanszky J, Hyblova M, Durovcikova D, Hikkelova M, Fiedler E, Kadasi L, Turna J, Minarik G, and Szemes T. Complex phenotypes blur conventional borders between Say-Barber-Biesecker-Young-Simpson syndrome and genitopatellar syndrome. Clin Genet. July 25 2016; [Epub ahead of print]:https://www.ncbi.nlm.nih.gov/pubmed/27452416.
  2. Gannon T, Perveen R, Schlecht H, et al. Further delineation of the KAT6B molecular and phenotypic spectrum. European Journal of Human Genetics. 2015; 23(9):1165-70. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351891.
  3. Campeau PM and Lee BH. KAT6B-Related Disorders. GeneReviews. January 10 2013; https://www.ncbi.nlm.nih.gov/books/NBK114806.