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Start free with EleplanNijmegen breakage syndrome
ORPHA:647Malformation syndrome
Also called AT V1 · Ataxia-telangiectasia, variant 1 · Berlin breakage syndrome · Immunodeficiency-microcephaly-chromosomal instability syndrome · Microcephaly-immunodeficiency-lymphoid malignancy syndrome · NBS · Seemanova syndrome type 2
What it is
A rare, genetic chromosomal instability syndrome presenting at birth with microcephaly, dysmorphic facial features which become more noticeable with age, growth delay, recurring sinopulmonary infections and extremely high frequency of malignancies.
Key facts
- Prevalence
- <1 / 1 000 000 (Russian Federation)
- Age of onset
- Antenatal, 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%
31- Abnormal hair quantity
- Abnormality of chromosome stability
- Abnormality of the face
- Abnormality of the hair
- Anal atresia
- Anal stenosis
- Anorectal anomaly
- Attention deficit hyperactivity disorder
- Autoimmune hemolytic anemia
- Cachexia
- Chronic diarrhea
- Convex nasal ridge
- Deep philtrum
- Depressed nasal bridge
- Hearing abnormality
- Hemolytic anemia
- Low anterior hairline
- Macrotia
- Mental deterioration
- Microcephaly
- Prominent nasal bridge
- Prominent nose
- Recurrent pneumonia
- Recurrent respiratory infections
- Recurrent sinopulmonary infections
- Retrognathia
- Short neck
- Short stature
- Sloping forehead
- Thrombocytopenia
- Upslanted palpebral fissure
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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