Further Magnetic Resonance Imaging (MRI) Brain Delineation of 49,XXXXY Syndrome

Abstract

A rare sex chromosome aneuploidy syndrome, 49,XXXXY syndrome is characterized by mental retardation with severe learning difficulties, craniofacial and skeletal abnormalities, hypogonadism, and congenital heart disease. The authors describe a 30-month-old boy with 49,XXXXY syndrome, global developmental delay and white matter changes in the brain magnetic resonance imaging. They reviewed the literature to delineate a specific magnetic resonance imaging pattern of 49,XXXXY syndrome.

Brain morphological abnormalities in 49,XXXXY syndrome: A pediatric magnetic resonance imaging study

“…This child also had prominent ventricles and thin corpus callosum (García-Cazorla et al, 2004). Most recently, MRI results from a 30-month-old male demonstrated regional periventricular white matter abnormalities with a posterior predominance that also involved the spinothalamic tracts; a thin corpus callosum was also demonstrated (Tabarki et al, 2012). …”

48, XXXY/49, XXXXY mosaic: new neuroradiological features in an ultra-rare syndrome

“…Our case includes some of these (i.e., dysmorphisms and hip dysplasia) [ 6 ]. Gropman et al described patients with 48,XXXY syndrome with tics, intentional tremor and generalized hypotonia [ 7 ]. At present, only a mild generalized hypotonia emerged in our patient.…”

“…Brain abnormalities are frequently found in KS variants; in particular, loss of brain volume, ventriculomegaly, white matter hyperintensities (such as T2 hyperintensity signals ranging from extensive confluent white matter alterations to punctate foci), decreased width of the corpus callosum, and cortical atrophy are reported [ 5 , 7 ]. Therefore, the supernumerary X chromosome seems to have a negative effect on white matter and central nervous system (CNS) development [ 4 ].…”

Effects of sex chromosome dosage on corpus callosum morphology in supernumerary sex chromosome aneuploidies

“…Our results agree with the literature on MRI studies in SCA subjects. These reports primarily focus on 47,XXY [ 12 ]–[ 14 ],[ 52 ]–[ 54 ] and, to a lesser extent, higher order supernumerary X karyotypes [ 22 ],[ 55 ],[ 56 ]. These studies consistently report overall reductions in WM/GM volumes and higher ventricular volume.…”