APERT’S SYNDROME (acrocephalosyndactyly)

ULTRASOUND

• Autosomal Dominant.
• Recently found to be due to a specific substitution involving adjacent amino acids (Ser252Trp or Pro253Arg) in the linker between the second and third extracellular immunoglobulin domains of fibroblast growth factor receptor 2 (FGFR2) (1,2)
• Skull:
• Oxycephaly and flattened occiput.
• Hypertelorism and bilateral exophthalmos.
• Underdeveloped maxilla and prognathism (mid-facial hypoplasia), choanal atresia.
• Cervical spine may be fused.

• Hands and Feet:
• Fusion of distal portions of phalanges, metacarpals and carpals of 2nd, 3rd and 4th digit (Syndactyly).
• Absence of middle phalanges.
• Missing / supernumerary carpal / tarsal bones.
• Pseudoarthrosis.
• Broad distal thumb and big toes.

CLASSIFICATION

Link to classification of Acrocephalosyndactyly

REFERENCES

1. Cohen MM, Kreiborg S, Lammer EJ et.al. Birth prevalence study of Apert syndrome. Am J Med Genet 1992;42:655-659.
2. Wilkie AOM, Slaney SF, Oldridge M et.al. Apert syndrome results from localized mutations of FGR2 and is allelic with Crouzon syndrome. Nature Genet 1995;9:165-172.
3. Hill LM, Thomas ML, Peterson CS. The ultrasound detection of Apert syndrome. J Ultrasound Med 1987;6:601-604.
4. Pooh, Nakagawa Y, Pooh KH et.al. Fetal craniofacial and intracranial morphology in a case of Apert syndrome. Ultrasound Obstet Gynecol 1999;13:274-280.