Atypical Features in Angelman Syndrome Due to Imprinting Defect or Uniparental Disomy of Chromosome 15

Sir,

Clinical diagnostic criteria are now well defined for Angelman syndrome (AS) [[1], [12]], a neurogenetic disorder characterised by development delay, virtually absent speech, a complex motor impairment and a happy demeanour. Following recent molecular characterisation of the underlying defect on chromosome 15 q11 - 13, a number of new patients have come to medical attention. From the few dozen reported 10 years ago, there are now clinical data concerning hundreds of patients. Molecular confirmation of the diagnosis is possible in more than 80 %, but clinical diagnostic criteria remain applicable for all cases. Some subtle signs may escape attention and fall outside diagnostic criteria. In this regard, it may be of interest to report less typical aspects. We describe incomplete phenotypes and atypical presentations in two such cases.

References

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