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Start free with EleplanTBCK-related encephalopathy-severe hypotonia-craniofacial dysmorphism syndrome
ORPHA:488632Malformation syndrome
What it is
A rare multiple congenital anomalies/dysmorphic syndrome characterized by profound intellectual disability with absent speech, severe infantile hypotonia with decreased or absent reflexes, markedly slow motor development (with no progress beyond the ability to sit independently), early-onset epilepsy, strabismus and post-natal onset of progressive brain atrophy (including loss of brain volume, ex vacuo ventriculomegaly, dysgenesis of corpus callosum, white matter abnormalities ranging from non-specific changes to leukodystrophy). Swallowing difficulties, respiratory insufficiency, osteoporosis and variable craniofacial dysmorphisms (including plagio/brachycephaly, bitemporal narrowing, high-arched eyebrows high nasal bridge, anteverted nares, high palate, tented upper lip) may constitute additional clinical features.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Infancy, Neonatal
- Inheritance
- Autosomal recessive
- Classified as
- Malformation syndrome
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
Very common80–99%
4Common30–79%
16- Abnormal circulating lipid concentration
- Abnormal facial shape
- Abnormal periventricular white matter morphology
- Areflexia
- Coarse facial features
- Delayed speech and language development
- Global brain atrophy
- Hypoplasia of the corpus callosum
- Inability to walk
- Multifocal seizures
- Reduced tendon reflexes
- Respiratory insufficiency
- Seizure
- Severe global developmental delay
- Skeletal muscle atrophy
- Ventriculomegaly
Sometimes5–29%
22- Broad forehead
- Bulbous nose
- Cognitive impairment
- Delayed skeletal maturation
- Developmental regression
- EEG with generalized epileptiform discharges
- EMG: myokymic discharges
- Epicanthus
and 14 more in this range
Rare1–4%
31- 11 pairs of ribs
- 2-3 toe syndactyly
- Abnormal involuntary eye movements
- Asthma
- Autism
- Bipolar affective disorder
- Broad finger
- Broad toe
and 23 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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