TY - JOUR
T1 - Treatment experience in two adults with creatinfe transporter deficiency
AU - Schjelderup, Jack
AU - Hope, Sigrun
AU - Vatshelle, Christian
AU - van Karnebeek, Clara D. M.
N1 - Funding Information: CvK's work is supported by Stichting Metakids. Publisher Copyright: © 2021 The Authors
PY - 2021/6/1
Y1 - 2021/6/1
N2 - Background: Creatine transporter deficiency (CTD) is an X-linked form of intellectual disability (ID) caused by SCL6A8 mutations. Limited information exists on the adult course of CTD, and there are no treatment studies in adults. Methods: We report two half-brothers with CTD, 36 and 31 years at intervention start. Their clinical phenotypes were consistent with CTD, and intervention was indicated because of progressive disease course, with increased difficulties speaking, walking and eating, resulting in fatigue, and malnutrition. We therefore performed treatment trials with arginine, glycine and a proprietary product containing creatine and betaine, and then a trial supplementing with betaine alone. Results: In the older patient, glycine and arginine were accompanied by adverse effects, while betaine containing proprietary product gave improved balance, speech and feeding. When supplementation stopped, his condition deteriorated, and improved again after starting betaine supplement. Betaine supplementation was also beneficial in the younger patient, reducing his exhaustion, feeding difficulties and weight loss, making him able to resume his protected work. Discussion & conclusion: We report for the first time that betaine supplement was well tolerated and efficient in adults with CTD, while arginine and/or glycine were accompanied by side effects. Thus, betaine is potentially a new useful treatment for CTD patients. We discuss possible underlying treatment mechanisms. Betaine has been reported to have antagonistic effect on NKCC1 channels, a mechanism shared with bumetanide, a medication with promising results in both in autism and epilepsy. Further studies of betaine's effects in well-designed studies are warranted.
AB - Background: Creatine transporter deficiency (CTD) is an X-linked form of intellectual disability (ID) caused by SCL6A8 mutations. Limited information exists on the adult course of CTD, and there are no treatment studies in adults. Methods: We report two half-brothers with CTD, 36 and 31 years at intervention start. Their clinical phenotypes were consistent with CTD, and intervention was indicated because of progressive disease course, with increased difficulties speaking, walking and eating, resulting in fatigue, and malnutrition. We therefore performed treatment trials with arginine, glycine and a proprietary product containing creatine and betaine, and then a trial supplementing with betaine alone. Results: In the older patient, glycine and arginine were accompanied by adverse effects, while betaine containing proprietary product gave improved balance, speech and feeding. When supplementation stopped, his condition deteriorated, and improved again after starting betaine supplement. Betaine supplementation was also beneficial in the younger patient, reducing his exhaustion, feeding difficulties and weight loss, making him able to resume his protected work. Discussion & conclusion: We report for the first time that betaine supplement was well tolerated and efficient in adults with CTD, while arginine and/or glycine were accompanied by side effects. Thus, betaine is potentially a new useful treatment for CTD patients. We discuss possible underlying treatment mechanisms. Betaine has been reported to have antagonistic effect on NKCC1 channels, a mechanism shared with bumetanide, a medication with promising results in both in autism and epilepsy. Further studies of betaine's effects in well-designed studies are warranted.
KW - Adult
KW - Arginine
KW - Betaine
KW - Creatine
KW - Creatine transporter deficiency
KW - Glycine
KW - Intellectual disability
KW - Supplementation
KW - Taurine
KW - Treatment
UR - http://www.scopus.com/inward/record.url?scp=85101313487&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.ymgmr.2021.100731
DO - https://doi.org/10.1016/j.ymgmr.2021.100731
M3 - Article
C2 - 33665121
SN - 2214-4269
VL - 27
JO - Molecular Genetics and Metabolism Reports
JF - Molecular Genetics and Metabolism Reports
M1 - 100731
ER -