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Start free with EleplanProximal 16p11.2 microduplication syndrome
ORPHA:370079Malformation syndrome
Also called Proximal dup(16)(p11.2) · Proximal trisomy 16p11.2
What it is
Proximal 16p11.2 microduplication syndrome is a rare chromosomal anomaly syndrome resulting from a partial duplication of the short arm of chromosome 16 characterized by developmental delay and intellectual disability of a highly variable degree, autism spectrum, obsessive-compulsive, attention deficit hyperactivity disorder, speech articulation abnormalities, muscular hypotonia, tremor, hyper- or hyporeflexia, seizures, microcephaly, neuroimaging abnormalities, decreased body mass index and schizophrenia or bipolar disorder later on in life.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Infancy, Neonatal
- 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%
21- Abnormal basal ganglia MRI signal intensity
- Arachnodactyly
- Decreased body mass index
- Deeply set eye
- Delayed speech and language development
- Failure to thrive
- Flat face
- Hypertelorism
- Hyporeflexia
- Hypotonia
- Intellectual disability
- Microcephaly
- Microtia
- Motor delay
- Short stature
- Smooth philtrum
- Sparse eyebrow
- Sparse eyelashes
- Speech articulation difficulties
- Thin upper lip vermilion
- Tremor
Common30–79%
6Sometimes5–29%
9- Abnormality of the hairline
- Autism
- Bipolar affective disorder
- Congenital diaphragmatic hernia
- Frontal bossing
- Schizophrenia
- Scoliosis
- Seizure
and 1 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.
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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