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Start free with EleplanGlobal developmental delay-alopecia-macrocephaly-facial dysmorphism-structural brain anomalies syndrome
ORPHA:544488Disease
Also called Bachmann-Bupp syndrome · Ornithine decarboxylase deficiency
What it is
A rare disorder of ornithine metabolism characterized by global developmental delay, alopecia, macrocephaly, and dysmorphic facial features (including high and broad forehead, hypertelorism, ptosis, blepharophimosis, downslanting palpebral fissures, deep-set eyes, large ears, and retrognathia or high arched palate). Additional reported manifestations are sensorineural hearing loss, spasticity, hypotonia, hypoplastic nails, cryptorchidism, and clinodactyly, among others. Brain imaging may show white matter abnormalities, periventricular cysts, enlarged lateral ventricles, or prominent perivascular spaces.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Antenatal, 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%
19- Absent eyebrow
- Aggressive behavior
- Attention deficit hyperactivity disorder
- Bilateral cryptorchidism
- Bilateral ptosis
- Bulbous nose
- Deeply set eye
- Dilation of Virchow-Robin spaces
- Global developmental delay
- Hyperintensity of cerebral white matter on MRI
- Hypertelorism
- Large forehead
- Large for gestational age
- Macrocephaly
- Macrotia
- Neonatal hypotonia
- Polyhydramnios
- Small nail
- Sparse eyelashes
Sometimes5–29%
37- Abnormality of the cerebellar vermis
- Absent eyelashes
- Absent speech
- Alopecia
- Asthma
- Atypical behavior
- Blepharophimosis
- Broad forehead
and 29 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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