Neuropediatrics 2016; 47(01): 051-056
DOI: 10.1055/s-0035-1566233
Short Communication
Georg Thieme Verlag KG Stuttgart · New York

Xp11.22 Microduplications Including HUWE1: Case Report and Literature Review

Sonia Orivoli
1   Child Neuropsychiatry Unit, Department of Neuroscience, University-Hospital of Parma, Parma, Italy
,
Elena Pavlidis
1   Child Neuropsychiatry Unit, Department of Neuroscience, University-Hospital of Parma, Parma, Italy
,
Gaetano Cantalupo
2   Child Neuropsychiatry Unit, Department of Life and Reproduction Sciences, University of Verona, Verona, Italy
,
Marianna Pezzella
3   Muscular and Neurodegenerative Disease Unit, Institute G. Gaslini, Genova, Italy
,
Federico Zara
3   Muscular and Neurodegenerative Disease Unit, Institute G. Gaslini, Genova, Italy
,
Livia Garavelli
4   Clinical Genetics Unit, IRCCS, S. Maria Nuova Hospital, Reggio Emilia, Italy
,
Francesco Pisani
1   Child Neuropsychiatry Unit, Department of Neuroscience, University-Hospital of Parma, Parma, Italy
,
Benedetta Piccolo
5   Child Neuropsychiatry Unit, Mother and Child Department, University-Hospital of Parma, Parma, Italy
› Author Affiliations
Further Information

Publication History

19 June 2015

12 September 2015

Publication Date:
20 November 2015 (online)

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Abstract

Xp11.22 microduplications have been reported in different patients with X-linked intellectual disability. Comparing the duplicated segments, a minimum region of overlap has been identified. Within this region, only one gene, the HUWE1 gene, coding the E3 ubiquitin protein ligase, turned out to be duplicated in all previously described patients. We provide a review of the literature on this topic, making a comparison not only of genetic aspects, but also of clinical, neurophysiological, and neuroradiological findings. Furthermore, we describe the phenotypic and molecular characterization of a case of intellectual disability in a child carrying one of the smallest Xp11.22 microduplications reported, involving the whole sequence of HUWE1 gene. Unlike previously described cases, our patient's neuroimaging showed abnormal findings; he also experienced one seizure and showed interictal electroencephalogram (EEG) epileptiform abnormalities. Given the fact that HUWE1 duplications and mutations have previously been described in several patients with X-linked cognitive impairment, our findings support the hypothesis that HUWE1 gene might be implicate in the pathogenesis of intellectual disability. Nevertheless, further investigations and a more detailed examination of patients' clinical history are needed to clear up other eventual genotype–phenotype correlations, such as the presence of epilepsy/epileptiform EEG abnormalities.