Prevalence:

• 1 in 20,000 births.

Ultrasound diagnosis:

• Spectrum of hand and foot defects with missing digits, median cleft and fusion of the remaining digits resulting in clawlike extremities.

Associated abnormalities:

• Chromosomal abnormalities: found in trisomy 18.
• High incidence of genetic syndromes. The most common are:
  • Roberts syndrome: autosomal recessive; ectrodactyly, phocomelia, facial cleft.
  • Ectrodactyly - ectodermal dysplasia (EEC): autosomal dominant; deferomities of all four extremities but more severe in the hands, and ectodermal defects (dry skin, sparse hair, dental defects and defects of the tear ducts).
  • Nager syndrome: autosomal dominant but in most cases de novo mutations; ectrodactyly, micrognathia, external ear anomalies.
  • Split hand and foot malformation: ectrodactyly presenting as ‘lobster claw’ anomaly.

Investigations:

• Detailed ultrasound examination.
• Invasive testing for karyotyping and array.

Follow up:

• Standard follow-up.
• Consultation by a clinical geneticist.

Delivery:

• Standard obstetric care and delivery.

Prognosis:

• Isolated: good prognosis.
• Surgical treatment and physiotherapy reduce functional impairment of the hands.

Recurrence:

• Isolated familial: 50%.