Hao-Fountain syndrome

What it is

A rare genetic intellectual disability syndrome characterized by global developmental delay, intellectual disability, severe speech delay, behavioral abnormalities (including impulsivity, compulsivity, stubbornness, manipulative behaviors, temper tantrums, and aggressive behaviors), autism spectrum disorder and mild and variable dysmorphic facies (including deep-set eyes and a prominent nasal septum, extending below the alae nasi) due to point mutation of USP7 gene or 16p13.2 microdeletion where USP7 is completely or partially deleted. Behavioral abnormalities are more pronounced in microdeletion. Patients may also have hypotonia, feeding problems, delayed walking with unsteady gait, hypogonadism in males, seizures and ocular anomalies (such as myopia, esotropia, strabismus, and nystagmus).

Key facts

Prevalence

<1 / 1 000 000

Age of onset

Infancy, Neonatal

Inheritance

Autosomal dominant

Classified as

Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Genes reported in subtypes

Orphanet records this gene on 2 more specific entries under this disorder, not on this entry itself:

A well-studied disease is usually split into subtypes, and the gene is curated on whichever one the evidence belongs to. Open a subtype to see which gene goes with it.

ICD-10 codes

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references