POLR3A and POLR3B Mutations in Unclassified Hypomyelination

• DOI: 10.1055/s-0035-1550148
• Publication Date: 2015-05-26T22:35:51Z
• Authors: Rosalina van Spae...; Miriam Nickel; Annette Bley; Kether Guerrero; Luan Tran; Marjo van der Knaap; Geneviève Bernard; Ferdy Cayami; Roberta La Piana; Nicole Wolf
• Keywords: Compound heterozygosity; Heterozygote advantage

<b>Objective</b> This study aims to ascertain frequency of mutations in <i>POLR3A</i> or <i>POLR3B</i>, which are associated with 4H leukodystrophy, a cohort patients unclassified hypomyelination. <b>Methods and Results</b> In 22 the magnetic resonance imaging (MRI) diagnosis hypomyelination without typical clinical signs, we evaluated MRI features. Developmental delay intellectual disability, ataxia, spasticity were frequent symptoms. <i>POLR3B</i> sequenced. A compound heterozygote mutation was found only one patient. Additional investigations allowed definitive 10 patients. <b>Conclusion</b> Mutations rare hypomyelination, alternative diagnoses should be considered first.