Differential Diagnosis for Neonate with Limb Deformity and Fusion of Fingers

Single Most Likely Diagnosis

• Syndactyly: This condition is characterized by the fusion of two or more digits, which can be seen in isolation or as part of various genetic syndromes. It's a relatively common congenital anomaly that fits the description provided.

Other Likely Diagnoses

• Polydactyly: Although this condition involves extra fingers or toes rather than fusion, it often occurs in conjunction with syndactyly and can be part of the same spectrum of limb abnormalities.
• Amniotic Band Syndrome: This condition occurs when the inner layer of the placenta (amnion) tears without injury to the outer layer, and the baby is entangled in the fibrous bands. It can cause a variety of limb deformities, including fusion of fingers.
• Apert Syndrome: A genetic disorder characterized by the premature fusion of bones in the skull (craniosynostosis) and often syndactyly of the hands and feet.

Do Not Miss Diagnoses

• Edward Syndrome (Trisomy 18): A genetic disorder due to an extra copy of chromosome 18. It can cause severe limb abnormalities, among other serious health issues. Early diagnosis is crucial for management and prognosis.
• Moebius Syndrome: A rare neurological disorder characterized by facial paralysis and impaired eye movement, which can also include limb abnormalities. Missing this diagnosis could lead to delayed intervention for associated complications.

Rare Diagnoses

• Sirenomelia: A rare congenital disorder characterized by the fusion of the lower limbs, giving the appearance of a mermaid's tail. It's often associated with other severe anomalies.
• Ectrodactyly: Also known as "lobster claw" syndrome, it involves the absence of one or more fingers or toes and can include fusion of the remaining digits.
• Constriction Band Syndrome: Similar to amniotic band syndrome but typically involves deeper, more pronounced bands that can cause significant limb deformity or even amputation in utero.

Each of these conditions has distinct features, but they can all present with limb deformities and fusion of fingers to varying degrees. A thorough clinical examination, family history, and possibly genetic testing are essential for an accurate diagnosis.