Bohring–Opitz syndrome (BOS) is a medical

syndrome A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired ...

caused by a mutation in the ''

ASXL1 Putative Polycomb group protein ASXL1 is a protein that in humans is encoded by the ''ASXL1'' gene. In Drosophila, the Additional sex combs (Asx) gene encodes a chromatin-binding protein required for normal determination of segment identity in th ...

'' gene.

Presentation

This condition is characterised by characteristic

craniofacial Craniofacial (''cranio-'' combining form meaning head or skull + ''-facial'' combining form referring to the facial structures grossly) is an adjective referring to the parts of the head enclosing the brain and the face. The term is typically used ...

appearance, fixed

contractures In pathology, a contracture is a permanent shortening of a muscle or joint. It is usually in response to prolonged hypertonic spasticity in a concentrated muscle area, such as is seen in the tightest muscles of people with conditions like spasti ...

of the upper limbs, abnormal posture,

feeding difficulties Dysphagia is difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, in some contexts it is classified as a disease#Terminology, condition in its own right. It may be a sensation that suggests difficulty in the passag ...

intellectual disability Intellectual disability (ID), also known as general learning disability in the United Kingdom and formerly mental retardation,Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010). is a generalized neurodevelopmental disorder characterized by signifi ...

, small size at birth and

failure to thrive Failure to thrive (FTT), also known as weight faltering or faltering growth, indicates insufficient weight gain or absence of appropriate physical growth in children. FTT is usually defined in terms of weight, and can be evaluated either by a low ...

. Children with BOS can also have recurring

respiratory infections Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...

, silent aspiration,

sleep apnea Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many times ...

developmental delay Global developmental delay is an umbrella term used when children are significantly delayed in their cognitive and physical development. It can be diagnosed when a child is delayed in one or more milestones, categorised into motor skills, speech, c ...

, abnormal hair density and length,

Wilms' tumors Wilms' tumor or Wilms tumor, also known as nephroblastoma, is a cancer of the kidneys that typically occurs in children, rarely in adults.; and occurs most commonly as a renal tumor in child patients. It is named after Max Wilms, the German surg ...

, brain abnormalities, and other issues.

Genetics

Genetically, de novo truncating mutations in ''ASXL1'' have been shown to account for approximately 50% of Bohring–Opitz syndrome cases. A second gene associated with this condition is the Kelch-like family member 7 ( KLHL7).

Diagnosis

As some of these features are shared with other

genetic syndromes A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired ...

, the diagnosis is made by

genetic testing Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

Epidemiology

The syndrome is extremely rare, with fewer than 80 reported cases worldwide.

References

External links

Rare genetic syndromes Syndromes with craniofacial abnormalities Syndromes with intellectual disability {{genetic-disorder-stub