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Start free with EleplanPHIP-related behavioral problems-intellectual disability-obesity-dysmorphic features syndrome
ORPHA:589905Disease
Also called Chung-Jansen syndrome · DIDOD
What it is
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by variable developmental delay and intellectual disability, overweight or obesity, behavioral abnormalities (including hyperactivity, aggressive behavior, anxiety, mood disorder, or autistic features), and facial dysmorphism (such as high forehead, full eyebrows and/or synophrys, upturned nose, and fleshy ears, among others). Additional reported manifestations are hypotonia, ocular anomalies, anomalies of the fingers and toes, joint hypermobility, or abnormal pigmentation. Brain imaging may show mild nonspecific abnormalities.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Antenatal, 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.
Signs and symptoms
Common30–79%
18- Abnormality of refraction
- Anteverted nares
- Attention deficit hyperactivity disorder
- Broad nasal tip
- Cafe-au-lait spot
- Clinodactyly of the 5th finger
- Fatigue
- Feeding difficulties in infancy
- High forehead
- Hypermetropia
- Hypertelorism
- Hypotonia
- Impulsivity
- Increased body weight
- Long philtrum
- Synophrys
- Tapered finger
- Thin vermilion border
Sometimes5–29%
17- 2-3 toe syndactyly
- Almond-shaped palpebral fissure
- Constipation
- Cryptorchidism
- Epicanthus
- Gait disturbance
- Gastroesophageal reflux
- Generalized joint hypermobility
and 9 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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