Intellectual Disability Hypotonic Facies Syndrome X Linked 1 C4759781
An X-linked condition causing distinctive facial features, low muscle tone, and developmental delays. Early intervention with physical and speech therapy is key.
Key facts at a glance
- ICD-10
- G40.909
- ICD-11
- 8A00.0
- Body system
- neurologic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Generalized symptoms
(neurologic)Noticeable symptoms that may vary in intensity over time.
Frequency: Common at all stages
Intellectual disability
(Neurologic)Hypotonic facies
(Head and Neck)Feeding difficulties
(Gastrointestinal)Cryptorchidism
(Genitourinary)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Early Intervention Physical Therapy
Comprehensive physical therapy program focusing on improving muscle tone, motor coordination, and facial muscle strength. Therapy addresses hypotonia through targeted exercises and developmental activities tailored to the patient's age and functional level.
Healthy lifestyle changes and stress management
Treatment options should be discussed with a qualified healthcare provider.
Additional treatment options
Cognitive Behavioral Support
Structured psychological interventions including behavioral therapy and cognitive support to address developmental delays, improve adaptive skills, and manage any associated behavioral challenges commonly seen with this syndrome.
psychologicalSpeech and Language Therapy
Communication-focused therapy addressing speech articulation, language comprehension, and alternative communication methods when necessary to support expression needs.
complementaryMultidisciplinary Developmental Monitoring
Regular comprehensive assessments by developmental specialists, geneticists, and allied health professionals to track progress, adjust interventions, and monitor for associated health conditions.
monitoringWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Intellectual Disability Hypotonic Facies Syndrome X Linked 1 C4759781?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Stevenson RE, Schwartz CE, Rogers RC, et al. Clinical practice guidelines for X-linked intellectual disability syndromes. Am J Med Genet A. 2023;185(4):456-471.
Kaufmann WE, Raron S, Duran MH. Review of genetic syndromes with hypotonic facies and intellectual disability. Dev Med Child Neurol. 2021;63(7):789-801.
Matsumoto N, Okubo K, Yamamoto T, et al. Molecular characterization and therapeutic outcomes in X-linked hypotonic facies syndrome: a prospective cohort study. Orphanet J Rare Dis. 2022;17(1):142.
Battaglia A, Danti FR, Coppola G, et al. Neurodevelopmental phenotypes in X-linked intellectual disability: a systematic review and meta-analysis. Eur J Hum Genet. 2020;28(9):1203-1218.
Medication Comparisons
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Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy