1 Aarskog Syndrome
Faciodigitogenital syndrome, faciogenital dysplasia, FGDY
Hypertelorism, mild ptosis, anteverted nostrils, small nose, broad philtrum, clinodactyly
Frequency: More than 100 male cases reported.
Genetics
X-linked dominant with full male-female expression (OMIM 305400); the signal transduction FGDY gene is located at Xp11.21; autosomal dominant cases reported (OMIM 100050).
Clinical Features
• Mild to moderate short stature
• Characteristic facies (round face, hypertelorism, antimongoloid slant of palpebral fissures, ptosis, broad nasal bridge, small nose, anteverted nares, broad philtrum, maxillary hypoplasia, changing phenotype with age)
• Scrotal folds encircling penis ventrally (shawl scrotum), cryptorchidism
• Small hands and feet, brachydactyly
• Digital contractures (flexion of distal interpha- langeal joints, and hyperextension of proximal in- terphalangeal joints)
• Short thumbs
• Dental malocclusion
• Mild, inconstant mental retardation
• Lax joints
Differential Diagnosis
• Noonan syndrome
• Robinow syndrome
Radiographic Features Hands and Feet
• Brachydactyly
• Fifth finger clinodactyly
• Mild interdigital webbing
• Camptodactyly
• Broad thumbs and great toes
• Hypoplastic distal phalanges of fingers
• Hypoplastic middle phalanges of toes
• Fused middle and distal phalanges of toes Spine
• Cervical vertebral anomalies (hypoplasia, fusion, spina bifida occulta)
• Odontoid anomaly
• Disc space calcification (thoracic) Skull
• Maxillary hypoplasia Chest
• 13 pairs of ribs
• Mild pectus excavatum
Generalized Skeletal Abnormalities
• Delayed bone age
Bibliography
Fryns JP. Aarskog syndrome: the changing phenotype with age. Am J Med Genet 1992; 43: 420–7
Hoo JJ. The Aarskog (facio-digito-genital) syndrome. Clin Genet 1979; 16: 269–76
Pasteris NG, Cadle A, Logie LJ, Porteous MEM, Schwartz CE, Stevenson RE, Glover TW, Wilroy RS, Gorski JL. Isolation and analysis of the faciogenital dysplasia (Aarskog-Scott syndrome) gene: a putative, rho/rac guanine nucleotide ex- change factor. Cell 1994; 79: 669–78
Porteous MEM, Goudie DR. Aarskog syndrome. J Med Genet 1991; 28: 44–7
Teebi AS, Rucquoi JK, Meyn MS. Aarskog syndrome: report of a family with review and discussion of nosology. Am J Med Genet 1993; 46: 501–9
Aarskog Syndrome 576
Aarskog Syndrome 577
A
Fig. 1.1 a–c. Patient 1, age 5 years. a There is striking hyper- telorism, antimongoloid slant of palpebral fissures, and bilat- eral ptosis in this child. Note small nose, anteverted nares, broad philtrum, slight crease below the lower lip, and mild pectus excavatum. b Interdigital webbing. c ‘Shawl’ scrotum and mildly prominent umbilicus
a
b
c
Fig. 1.2. Patient 2, age 6 years. Note maxillary hypoplasia, resulting in flat face. The angle of the mandible is wider than normal
Aarskog Syndrome 578
Fig. 1.3 a, b. Patient 2, 6 years.
a Brachydactyly, with shortening of the metacarpals (especially 4th and 5th) and distal phalanges. The middle phalanges of the 5th fin- gers are markedly short, cone- shaped, and clinodactylous. The thumbs are relatively broad. Note also partial interdigital webbing, most pronounced between fingers 2 and 3. b The great toes are rela- tively broad, the middle phalanges of the toes are mildly hypoplastic
a
b
