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Start free with EleplanHelsmoortel-Van der Aa syndrome
ORPHA:404448Malformation syndrome
Also called ADNP syndrome · ADNP-related Helsmoortel-Van der Aa syndrome · ADNP-related syndromic intellectual disability-autism spectrum disorder · HVDAS
What it is
A rare neurodevelopmental disorder characterized by intellectual disability (ID), autistic features, gastrointestinal problems, hypotonia, delayed speech, behavioral and sleep problems, pain insensitivity, seizures, structural brain anomalies, dysmorphic features, and visual problems.
Key facts
- Age of onset
- Childhood, Infancy
- Inheritance
- Unknown
- Classified as
- Malformation syndrome
Signs and symptoms
Very common80–99%
6Common30–79%
14- Abnormality of brain morphology
- Abnormality of finger
- Abnormal temper tantrums
- Anxiety
- Attention deficit hyperactivity disorder
- Chronic constipation
- Compulsive behaviors
- Floppy infant
- Gastroesophageal reflux
- Joint hypermobility
- Moderate global developmental delay
- Oral-pharyngeal dysphagia
- Polyphagia
- Severe global developmental delay
Sometimes5–29%
39- Abnormal cardiovascular system morphology
- Abnormality of toe
- Abnormal nail morphology
- Advanced eruption of teeth
- Aggressive behavior
- Aspiration
- Astigmatism
- Bilateral ptosis
and 31 more in this range
Rare1–4%
21- 2-3 toe syndactyly
- Amblyopia
- Brachycephaly
- Brachydactyly
- Broad hallux
- Broad thumb
- Cryptorchidism
- Depressed nasal bridge
and 13 more in this range
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Gene
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
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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