title: Severe Hunter syndrome (mucopolysaccharidosis II) phenotype secondary to large deletion in the X chromosome encompassing IDS, FMR1, and AFF2 (FMR2).
abstract: A 2-year-old boy with an initial diagnosis of Hunter syndrome (mucopolysaccharidosis II) had a more severe phenotype than expected, which warranted further evaluation. The patient had severe infantile global neurodevelopmental delays, macrocephaly with a prominent forehead, coarse facial features with clear corneas, chronic congestion with snoring, wide-spaced teeth, short thick neck, hepatomegaly, an inguinal hernia repaired, early clawhand deformities, and severe generalized hypotonia. X chromosome microarray revealed a large deletion encompassing the genes IDS, FMR1, and AFF2 (FMR2) confirming the diagnoses of both Hunter and fragile X syndromes. This case is also a reminder to clinicians that for optimum patient care, further diagnostic testing is warranted if there is concern that a patient's phenotype is more severe or complex than would be expected for the initial neurogenetic diagnosis.
authors.affiliation: College of Medicine, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Day M
authors.initials: DM
authors.lastname: Burruss
authors.forename: Tim C
authors.initials: TC
authors.lastname: Wood
authors.forename: Lesby
authors.initials: L
authors.lastname: Espinoza
authors.forename: Alka
authors.initials: A
authors.lastname: Dwivedi
authors.forename: Kenton R
authors.initials: KR
authors.lastname: Holden
mesh_terms: D002675:Child, Preschool; D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D041321:Chromosomes, Human, X; D051860:Fragile X Messenger Ribonucleoprotein 1; D005600:Fragile X Syndrome / Q000150:complications / Q000235:genetics*; D006023:Glycoproteins; D006801:Humans; D008297:Male; D016532:Mucopolysaccharidosis II / Q000150:complications / Q000235:genetics*; D009687:Nuclear Proteins; D017384:Sequence Deletion / Q000235:genetics*
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; D006023:Glycoproteins; D009687:Nuclear Proteins; C099930:AFF2 protein, human; C497683:FMR1 protein, human; C018322:IDS protein, human