Aarskog syndrome or facio-digito-genital dysplasia is a rare X-linked condition associated with typical facial and digital features and shawl scrotum. The facial features include widow`s peak, hypertelorism, upturned nose and curved linear groove below lower lip. Hands and feet are short and broad. Interdigital webbing and clinodactyly may be present. The swan neck deformity of fingers due to hyperextension of proximal interphalangeal joints and flexion at distal interphalangeal joints are characteristic. The other features which may be present include cryptorchidism, downward slant of eyes, maxillary hypoplasia, cup-shaped ears, ptosis and in childhood, edema of limbs. Shawl scrotum in children with short stature is characteristic of Aarskog syndrome but may not be seen in 20% cases. The cases are diagnosed because of short stature or intellectual deficit. Initially height is less than third percentile but usually catches up at puberty. A study has shown positive effect of growth hormone treatment on growth and adult height. About 30 % of cases may have intellectual deficit, which usually is mild. The social integration of these patients and their life as adults are satisfactory. Sexual development is normal but may be delayed. Fertility is reported. The facial features become less obvious with age. Intrafamilial variability can be observed. The syndrome is caused by mutation in the FGD1 gene (faciogenital dysplasia type 1) that is mapped to Xp11.21. The mutation in this gene has been also found to cause intellectual deficit without other features of Aarskog syndrome. Occasional families suggestive of autosomal inheritance are also reported.
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