P-6Unusual concurrence of Facio-scapulo-humeraldystrophy and Williams Syndrome in a youngboy

Facioscapulohumeral dystrophy (FSHD) is one of the most common muscular dystrophies, inherited as an autosomal dominant trait; it is characterized by the progressive weakening and loss of skeletal muscles, usually at face, shoulder girdle and upper arms level. The actual incidence may be estimated 1 in 7,500. Infantile FSHD is a more severe and early onset form of FSHD, recently categorized as a subtype of FSHD, with onset in early childhood. There is no generally accepted estimate of its incidence, but it is rare. Both adult and infantile disorders are associated by genetic testing to the deletion of 3.3-kb repeats at the 4q35-qter locus. Patients with the fewest repeats typically present with the most severe symptoms. Williams syndrome (WS) is a rare genetic disease characterised by a developmental disorder associating a cardiac malformation (most frequently supra valvular aortic stenosis, SVAS) in 75% of cases, psychomotor retardation, a characteristic facial dysmorphism and a specific cognitive and behavioural profile. It is caused by a hemizygous deletion on chromosome 7q11.23, with an incidence of typical forms of 1:20 000 births. However, most cases of WS are not inherited, but occur as random events during the formation of reproductive cells in a parent of an affected individual. Young children with WS have distinctive facial features including broad forehead, short nose with a broad tip, full cheeks, and wide mouth with full lips. We present the case of a boy, 14 year old, affected by both disorders. FSHD was inherited from his mother while the WS was caused by a de novo deletion in chromosome 7. The phenotype deriving from the concurrence of both diseases is described.