congenital unilateral hypoplasia of depressor anguli oris

Congenital unilateral hypoplasia of depressor anguli oris is a condition present from birth that affects the facial muscles, specifically resulting in an asymmetry when an infant cries. It is most characterized by the underdevelopment or absence of the muscle responsible for pulling down one corner of the mouth, leading to an asymmetric crying facies. The condition typically becomes evident during the neonatal period or infancy, and while it may be associated with other congenital anomalies in some cases, in its isolated form it tends to have minimal cosmetic and functional impact as the child grows. Prevalence data for this condition is not well established.

The hallmark feature of this condition is the asymmetric crying facies observed during infancy, where one side of the mouth droops while the other side maintains normal movement during crying. Although the eye closure, nasolabial fold, and forehead wrinkling remain symmetric, the noticeable imbalance is what typically prompts medical evaluation. Not all individuals will present with additional symptoms, and severity can vary considerably between affected persons.

The precise genetic basis of congenital unilateral hypoplasia of depressor anguli oris is not fully elucidated; however, the condition is reported to follow an autosomal dominant inheritance pattern. This means that a single altered copy of a gene, even though the specific gene responsible has not been identified, can lead to the development of the condition. In some cases, the anomaly may occur as part of a broader syndrome, such as 22q11.2 deletion syndrome, and genetic counseling is recommended to help families understand the implications and recurrence risks.

Currently, management focuses on supportive care and symptom management, especially since the condition is often cosmetically insignificant as the individual grows older. In cases where the anomaly is isolated, treatment is generally conservative and tailored to the patient’s needs, with regular follow‐up to monitor any associated anomalies if present. Families are encouraged to seek genetic counseling to better understand the inheritance pattern and to discuss appropriate management options with their healthcare team.

The overall outlook for individuals with congenital unilateral hypoplasia of depressor anguli oris is generally positive, particularly when the condition occurs in isolation. As the child grows, the cosmetic significance of the facial asymmetry often diminishes, and most individuals do not experience severe complications. However, when the anomaly is associated with other congenital anomalies, outcomes may vary. That severity and symptoms vary widely between individuals. Outcomes described in medical literature continue to evolve as standards of care improve, and families are encouraged to consult genetic counselors and specialists for personalized guidance.