Question 1

What is Hao-Fountain syndrome?

Accepted Answer

Hao-Fountain syndrome is a rare genetic disorder that affects development. People with this condition experience global developmental delays, intellectual challenges, and severe delays in speech. The condition is also marked by behavioral differences including impulsivity, stubbornness, and aggressive behaviors, as well as physical features such as deep-set eyes and a prominent nasal septum.

This syndrome is linked to changes in the USP7 gene or to a microdeletion in a specific region of the chromosome. These genetic differences can lead to other issues like hypotonia (low muscle tone), feeding difficulties, problems with walking, seizures, and various eye conditions. The behavioral challenges can sometimes be more noticeable when a microdeletion is involved.

Question 2

What are the symptoms of Hao-Fountain syndrome?

Accepted Answer

Common signs of Hao-Fountain syndrome include global developmental delay, intellectual disability, and severe speech delay. People with this condition may also show behavioral abnormalities such as impulsivity, stubbornness, temper tantrums, and aggressive behaviors. Some may have features of autism spectrum disorder. Additionally, there can be physical symptoms including hypotonia, feeding problems, delayed walking with an unsteady gait, and ocular issues like myopia, strabismus, and nystagmus.

Question 3

What causes Hao-Fountain syndrome?

Accepted Answer

Hao-Fountain syndrome is caused by genetic changes. It can result from a point mutation in the USP7 gene or from a microdeletion on chromosome 16p13.2 where the USP7 gene is partially or completely missing. The type of genetic change may influence the presence and severity of certain behaviors and other symptoms. Associated genes include USP7.

Question 4

How rare is Hao-Fountain syndrome?

Accepted Answer

Hao-Fountain syndrome is classified as very rare. The estimated prevalence is approximately <1 in 1,000,000. Because rare disease data can be limited, actual numbers may differ from published estimates.

Question 5

How is Hao-Fountain syndrome diagnosed?

Accepted Answer

Information about diagnosis is currently limited for this condition.

Question 6

Are there treatments for Hao-Fountain syndrome?

Accepted Answer

Information about treatment is currently limited for this condition.

Question 7

What complications can arise from Hao-Fountain syndrome?

Accepted Answer

Hao-Fountain syndrome can lead to several complications due to its effects on development. These may include hypotonia, which is low muscle tone, and feeding difficulties that can affect nutrition. Additionally, individuals may experience problems with walking and may have seizures or various eye conditions, which can impact daily life.

Question 8

How does Hao-Fountain syndrome affect daily life and management?

Accepted Answer

Living with Hao-Fountain syndrome can be challenging due to global developmental delays and behavioral differences. Daily life may involve special education services, speech therapy, and behavioral support to help manage impulsivity and aggression. Families may also need to adapt their routines to accommodate feeding difficulties and mobility issues.

Question 9

What is the prognosis for someone with Hao-Fountain syndrome?

Accepted Answer

Currently, there is limited information about the long-term prognosis for individuals with Hao-Fountain syndrome. The severity of symptoms can vary widely, and some individuals may face more significant challenges than others. Ongoing support and intervention can help improve quality of life, but specific life expectancy data is not available.

Question 10

Are there any specific specialists recommended for managing Hao-Fountain syndrome?

Accepted Answer

For managing Hao-Fountain syndrome, it is important to work with a team of specialists. This may include a developmental pediatrician, a speech therapist, and a behavioral therapist to address the various challenges associated with the condition. An eye specialist may also be needed for any ocular issues, ensuring comprehensive care for the individual.

Research Type	Count	% of Total
Laboratory research	9	60%

Feature	% of Persons w/Feature	Comment
Developmental delay	100%	—
Intellectual disability	50%	Most of those w/full-scale IQ 85 show specific learning disabilities.
Muscular hypotonia	73%-79%	This may transition to high muscle tone in later life.
Autism spectrum disorder	72%	—
Brain MRI anomalies	68%-73%	White matter paucity, hypoplastic corpus callosum
Abnormal/unsteady gait	66%	—
Feeding difficulties	55%	—
Dental issues	55%	—
Impaired bone mineralization	54%	May lead to fractures
Eye anomalies	53%-65%	Strabismus, refractive errors, nystagmus
Sleep disturbance	47%	Sleep apnea is present in almost 1/3 of affected persons.
Epilepsy	40%	—
Hyperphagia	39%	Mild to moderate
Macrocephaly	35%	—
GERD	37%-50%	—
Hypogonadism	25%-44% (males)	Incl micropenis /or undescended testes in males
Contractures	24%	—
Hearing loss	15%	GERD = gastroesophageal reflux disease; IQ = intellectual quotient Developmental delay and intellectual disability are common among affected individuals.

Kisho

Hao-Fountain syndrome

Overview

Clinical Presentation

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Evaluations Following Initial Diagnosis

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

Orphanet

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

Differential Diagnosis

Neurologic

Development

Psychiatric

Feeding

Therapies Under Investigation

Clinical Trials

Recent Publications

Hao-Fountain syndrome

Overview

Clinical Presentation

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Evaluations Following Initial Diagnosis

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

Orphanet

Subtypes

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

What is Hao-Fountain syndrome?

What are the symptoms of Hao-Fountain syndrome?

What causes Hao-Fountain syndrome?

How rare is Hao-Fountain syndrome?

How is Hao-Fountain syndrome diagnosed?

Are there treatments for Hao-Fountain syndrome?

What complications can arise from Hao-Fountain syndrome?

How does Hao-Fountain syndrome affect daily life and management?

What is the prognosis for someone with Hao-Fountain syndrome?

Are there any specific specialists recommended for managing Hao-Fountain syndrome?

Differential Diagnosis

Neurologic

Development

Psychiatric

Feeding

Therapies Under Investigation

Clinical Trials

Recent Publications