Ayşegül Gündüz1, Aslı Gündoğdu Eken2, Başar Bilgiç3, Hasmet A Hanagasi3, Kaya Bilgüvar4, Murat Günel4, A Nazlı Başak2, Sibel Ertan5. 1. İstanbul University, Cerrahpaşa School of Medicine, Department of Neurology, 34098, K.M.Paşa, Istanbul, Turkey. Electronic address: draysegulgunduz@yahoo.com. 2. Boğaziçi University, Department of Molecular Biology and Genetics, Neurodegeneration Research Laboratory, Istanbul, Turkey. 3. İstanbul University, İstanbul School of Medicine, Department of Neurology, Istanbul, Turkey. 4. Yale University, Medical School, Neurogenetics Department, New Haven, CT, USA. 5. İstanbul University, Cerrahpaşa School of Medicine, Department of Neurology, 34098, K.M.Paşa, Istanbul, Turkey.
Abstract
OBJECTIVE: FBXO7 mutations (PARK 15), first reported in 2008, are among the monogenic causes of early-onset parkinsonism. Classically, PARK 15 was suggested to correspond to previously described pallido-pyramidal syndrome. Here, we report clinical and genetic findings in a unique family of Kurdish origin with an FBXO7 mutation and presenting with diverse clinical phenotypes. METHODS: The family consisted of 14 members (12 offspring) of whom three were affected. Two of these three siblings were examined in our clinic. DNA samples from the index case and his elder sister were subjected to homozygosity mapping and exomic sequencing. RESULTS: The index case had progressive speech problems, severe apathy, chorea, and tics at presentation and developed very mild parkinsonism and postural instability after 3 years. His sister had young-onset asymmetric tremor-dominant parkinsonism with some atypical features, such as early development of postural instability, tics, and tachyphemic speech. She died of an akinetic-rigid condition and had not developed chorea. A homozygous R498X mutation was found in both patients (NM_012179; chr22:31,224,440). This result was further confirmed by Sanger sequencing in both patients, their consanguineous parents, and their maternal grandfather; the latter three were found to be heterozygous for the mutation (c.C1492T; p.R498X). CONCLUSIONS: The family presented here broadens the clinical spectrum of parkinsonism to include tics and chorea, in addition to the parkinsonian-pyramidal phenotype, in connection with FBXO7 mutations and points to an intrafamilial phenotypic variation.
OBJECTIVE:FBXO7 mutations (PARK 15), first reported in 2008, are among the monogenic causes of early-onset parkinsonism. Classically, PARK 15 was suggested to correspond to previously described pallido-pyramidal syndrome. Here, we report clinical and genetic findings in a unique family of Kurdish origin with an FBXO7 mutation and presenting with diverse clinical phenotypes. METHODS: The family consisted of 14 members (12 offspring) of whom three were affected. Two of these three siblings were examined in our clinic. DNA samples from the index case and his elder sister were subjected to homozygosity mapping and exomic sequencing. RESULTS: The index case had progressive speech problems, severe apathy, chorea, and tics at presentation and developed very mild parkinsonism and postural instability after 3 years. His sister had young-onset asymmetric tremor-dominant parkinsonism with some atypical features, such as early development of postural instability, tics, and tachyphemic speech. She died of an akinetic-rigid condition and had not developed chorea. A homozygous R498X mutation was found in both patients (NM_012179; chr22:31,224,440). This result was further confirmed by Sanger sequencing in both patients, their consanguineous parents, and their maternal grandfather; the latter three were found to be heterozygous for the mutation (c.C1492T; p.R498X). CONCLUSIONS: The family presented here broadens the clinical spectrum of parkinsonism to include tics and chorea, in addition to the parkinsonian-pyramidal phenotype, in connection with FBXO7 mutations and points to an intrafamilial phenotypic variation.
Authors: Simon Rw Stott; Suzanne J Randle; Sara Al Rawi; Paulina A Rowicka; Rebecca Harris; Bethany Mason; Jing Xia; Jeffrey W Dalley; Roger A Barker; Heike Laman Journal: J Pathol Date: 2019-08-06 Impact factor: 7.996