Rare Infectious Disease News

Disease Profile

Schaaf-Yang syndrome

Prevalence
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.

Unknown

Age of onset

#N/A

ICD-10

#N/A

Inheritance

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

no.svg

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

no.svg

X-linked
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.

no.svg

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

no.svg

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.

no.svg

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.

no.svg

Not applicable

no.svg

Other names (AKA)

Prader-Willi syndrome due to a point mutation; PWS due to a point mutation; MAGEL2-related Prader-Willi-like syndrome;

Categories

Congenital and Genetic Diseases; Endocrine Diseases; Female Reproductive Diseases;

Summary

Schaaf-Yang syndrome is a genetic condition that affects many parts of the body and is similar to Prader-Willi syndrome. Infants with this syndrome can have low muscle tone (hypotonia), feeding difficulties, developmental delay, intellectual disability, and autism spectrum disorder. They also typically have joint contractures, affecting the finger joints and sometimes the knees and elbows. This syndrome does not usually cause the high appetite seen in people with Prader-Willi syndrome. Schaaf-Yang syndrome is caused by a mutation in the MAGEL2 gene on chromosome 15. This syndrome is related to Prader-Willi syndrome because if MAGEL2 and several additional genes on chromosome 15 are missing or inactivated, then a person will develop Prader-Willi syndrome.[1][2]

Symptoms

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:
HPO ID
80%-99% of people have these symptoms
Abnormal facial shape
Unusual facial appearance
0001999
Cryptorchidism
Undescended testes
Undescended testis

[ more ]

0000028
Flexion contracture
Flexed joint that cannot be straightened
0001371
Infantile muscular hypotonia
Decreased muscle tone in infant
0008947
Infertility
0000789
Motor delay
0001270
Neonatal hypotonia
Low muscle tone, in neonatal onset
0001319
Poor suck
Poor sucking
0002033
30%-79% of people have these symptoms
Abdominal obesity
Central obesity
0012743
Abnormal temper tantrums
0025160
Absence of pubertal development
0008197
Autistic behavior
0000729
Brain imaging abnormality
0410263
Chronic constipation
Infrequent bowel movements
0012450
Clitoral hypoplasia
Small clitoris
Underdeveloped clit

[ more ]

0000060
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment

[ more ]

0100543
Decreased fetal movement
Less than 10 fetal movements in 12 hours
0001558
Decreased testicular size
Small testes
Small testis

[ more ]

0008734
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
Failure to thrive
Faltering weight
Weight faltering

[ more ]

0001508
Gastroesophageal reflux
Acid reflux
Acid reflux disease
Heartburn

[ more ]

0002020
Hypogonadism
Decreased activity of gonads
0000135
Hypoplastic labia minora
Underdeveloped inner lips
0000064
Hypothalamic luteinizing hormone-releasing hormone deficiency
0012287
Intellectual disability, borderline
Mental retardation, borderline
0006889
Intellectual disability, mild
Mental retardation, borderline-mild
Mild and nonprogressive mental retardation
Mild mental retardation

[ more ]

0001256
Kyphosis
Hunched back
Round back

[ more ]

0002808
Nasogastric tube feeding
0040288
Polyphagia
Voracious appetite
0002591
Primary amenorrhea
0000786
Reduced tendon reflexes
0001315
Scoliosis
0002650
Scrotal hypoplasia
Smaller than typical growth of scrotum
0000046
Short foot
Short feet
Small feet

[ more ]

0001773
Short stature
Decreased body height
Small stature

[ more ]

0004322
Skin-picking
0012166
Small hand
Disproportionately small hands
0200055
Small pituitary gland
0012506
Specific learning disability
0001328
Temperature instability
0005968
Ventriculomegaly
0002119
Weak cry
0001612
5%-29% of people have these symptoms
Abnormal rapid eye movement sleep
0002494
Almond-shaped palpebral fissure
Almond shaped eyes
Almond-shaped opening between the eyelids

[ more ]

0007874
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
Central hypothyroidism
0011787
Central sleep apnea
0010536
Chorioretinal hypopigmentation
0040030
Confusional arousal
0025237
Downturned corners of mouth
Downturned corners of the mouth
Downturned mouth

[ more ]

0002714
Esotropia
Inward turning cross eyed
0000565
Hip dysplasia
0001385
Hypopigmentation of hair
Loss of hair color
0005599
Hypopigmentation of the skin
Patchy lightened skin
0001010
Impaired temperature sensation
Abnormality of temperature sensation
Loss of temperature sensation

[ more ]

0010829
Impulsivity
Impulsive
0100710
Lethargy
0001254
Micropenis
Short penis
Small penis

[ more ]

0000054
Myopia
Close sighted
Near sighted
Near sightedness
Nearsightedness

[ more ]

0000545

Organizations

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

      In-Depth Information

      • 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.

        References

        1. Schaaf-Yang syndrome. Foundation for Prader-Willi Research. https://www.fpwr.org/schaaf-yang-syndrome/. Accessed 7/25/2017.
        2. Fountain MD, Aten E, Cho MT, et al. The phenotypic spectrum of Schaaf-Yang syndrome – 18 new affected individuals from 14 families. Genetics in medicine?: official journal of the American College of Medical Genetics. 2017; 19(1):45-52. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5116288/.

        Rare Infectious Disease News