bims-meglyc Biomed News
on Metabolic disorders affecting glycosylation
Issue of 2024–08–18
two papers selected by
Silvia Radenkovic, UMC Utrecht



  1. Eur Child Adolesc Psychiatry. 2024 Aug 14.
      ALG6-congenital disorder of glycosylation (ALG6-CDG) is a complex of rare inherited disorders caused by mutations in the ALG6 gene, which encodes the α-1,3-glucosyltransferase enzyme required for N-glycosylation. ALG6-CDG affects multiple systems and exhibits clinical heterogeneity. Besides developmental delays and neurological signs and symptoms, behavioral and psychological symptoms are also an important group of clinical features of ALG6-CDG. Here, we present the case of a 17-year-old Chinese girl with ALG6-CDG who first visited the psychiatric department with apathy, language reduction, and substupor symptoms. The psychiatric assessments and treatment processes performed are described and discussed in this report. During diagnostic process, we found a novel mutation, c.849delT, in ALG6 by whole-exome sequencing. The patient's symptoms improved with escitalopram and risperidone treatment. However, above a certain dosage, she was sensitive to extrapyramidal side effects. This study accumulates clinical experience for diagnosing and treating ALG6-CDG and improves our understanding of this rare genetic disorder.
    Keywords:  ALG6 gene; Antipsychotic treatment; Congenital disorder of glycosylation; Psychiatry assessment
    DOI:  https://doi.org/10.1007/s00787-024-02564-x
  2. BMC Med Genomics. 2024 Aug 12. 17(1): 207
       BACKGROUND: Congenital Myasthenic Syndromes (CMS) are rare genetic diseases, which share as a common denominator muscle fatigability due to failure of neuromuscular transmission. A distinctive clinical feature of presynaptic CMS variants caused by defects of the synthesis of acetylcholine is the association with life-threatening episodes of apnea. One of these variants is caused by mutations in the SLC5A7 gene, which encodes the sodium-dependent HC-3 high-affinity choline transporter 1 (CHT1). To our knowledge there are no published cases of this CMS type in Latin America.
    CASE PRESENTATION: We present two cases of CHT1-CMS. Both patients were males presenting with repeated episodes of apnea, hypotonia, weakness, ptosis, mild ophthalmoparesis, and bulbar deficit. The first case also presented one isolated seizure, while the second case showed global developmental delay. Both cases, exhibited incomplete improvement with treatment with pyridostigmine.
    CONCLUSIONS: This report emphasizes the broad incidence of CMS with episodic apnea caused by mutations in the SLC5A7 gene and the frequent association of this condition with serious manifestations of central nervous system involvement.
    Keywords:   SLC5A7 ; Choline transporter 1; Congenital myasthenic syndromes; Episodic apnea; Presynaptic
    DOI:  https://doi.org/10.1186/s12920-024-01977-6