Auriculocondylar syndrome 2B is a congenital condition that affects facial structure and involves neurological as well as developmental manifestations. It is associated with alterations in the PLCB4 gene, a key player in cellular signaling pathways. Typically, affected individuals exhibit a range of craniofacial and neurodevelopmental features from an early age, and the condition follows an autosomal recessive inheritance pattern. Precise prevalence estimates are not well established, and the symptoms can vary widely between individuals.

The clinical presentation of auriculocondylar syndrome 2B is marked by a distinct set of craniofacial features including full cheeks, mandibular condyle hypoplasia, micrognathia, narrow mouth, telecanthus, synophrys, narrow forehead, and unusual ear shapes such as a question mark ear and the presence of a postauricular skin tag. Affected individuals also frequently exhibit neurological features such as autistic behavior and hypoplasia of the corpus callosum, which may impact cognitive and developmental outcomes. Additional findings that are always present include hypotonia, sparse hair, and failure to thrive, while other features like feeding difficulties, omphalocele, and neonatal respiratory distress occur in a subset of patients. Not all individuals experience all these features, and severity varies considerably.

Auriculocondylar syndrome 2B is caused by pathogenic variants in the PLCB4 gene. The PLCB4 protein plays an important role in intracellular signaling, and disruptions in its function are believed to contribute to the abnormal development of facial and neurological structures. This condition is inherited in an autosomal recessive pattern, meaning that an affected child receives one altered copy of the gene from each parent. Families are encouraged to seek genetic counseling to understand recurrence risks and implications for family planning, especially when there is a history of consanguinity. Associated genes include PLCB4.