Anesthesia considerations in carbohydrate-deficient glycoprotein syndrome type I

Case report: The art of anesthesiology-Approaching a minor procedure in a child with MPI-CDG

Background: Protein glycosylation plays an important role in post-translational modification, which defines a broad spectrum of protein functions. Accordingly, infants with a congenital disorder of glycosylation (CDG) can have N-glycosylation, O-glycosylation, or combined N- and O-glycosylation defects, resulting in similar but different multisystem involvement. CDGs can present notable gastrointestinal and neurologic symptoms. Both protein-losing enteropathy and hypotonia affect the decision of using anesthetics. We reported a case of MPI-CDG with protein-losing enteropathy and muscular hypotonia that underwent different anesthesia approach strategies of vascular access. Here, we highlight why intubation with sevoflurane anesthesia and sparing use of muscle relaxants is the optimal strategy for such a condition. Case presentation: A 25-month-old girl, weighing 6.6 kg and 64 cm tall, suffered chronic diarrhea, hypoalbuminemia, and hypotonia since birth. Protein-losing enteropathy due to MPI-CDG was documented by whole-exome sequencing. She underwent three sedated surgical procedures in our hospital. The sedation was administered twice by pediatricians with oral chloral hydrate, intravenous midazolam, and ketamine, to which the patient showed moderate to late recovery from sedation and irritability the following night. The most recent one was administered by an anesthesiologist, where endotracheal intubation was performed with sevoflurane as the main anesthetic. The patient regained consciousness immediately after the operation. She had no complications after all three sedation/anesthesia interventions and was discharged 7 days later, uneventful after the third general anesthesia procedure. Conclusion: We performed safe anesthetic management in a 25-month-old girl with MPI-CDG using sevoflurane under controlled ventilation. She awoke immediately after the procedure. Due to the disease entity, we suggested bypassing the intravenous route to avoid excess volume for drug administration and that muscle relaxant may not be necessary for endotracheal intubation and patient immobilization when performing procedures under general anesthesia in CDG patients.

Consensus guideline for the diagnosis and management of mannose phosphate isomerase-congenital disorder of glycosylation

Mannose phosphate isomerase-congenital disorder of glycosylation (MPI-CDG) deficiency is a rare subtype of congenital disorders of protein N-glycosylation. It is characterised by deficiency of MPI caused by pathogenic variants in MPI gene. The manifestation of MPI-CDG is different from other CDGs as the patients suffer dominantly from gastrointestinal and hepatic involvement whereas they usually do not present intellectual disability or neurological impairment. It is also one of the few treatable subtypes of CDGs with proven effect of oral mannose. This article covers a complex review of the literature and recommendations for the management of MPI-CDG with an emphasis on the clinical aspect of the disease. A team of international experts elaborated summaries and recommendations for diagnostics, differential diagnosis, management, and treatment of each system/organ involvement based on evidence-based data and experts' opinions. Those guidelines also reveal more questions about MPI-CDG which need to be further studied.

Elevated thrombin generation in patients with congenital disorder of glycosylation and combined coagulation factor deficiencies

BACKGROUND

Congenital disorders of glycosylation are rare inherited diseases affecting many different proteins. The lack of glycosylation notably affects the hemostatic system and leads to deficiencies of both procoagulant and anticoagulant factors.

OBJECTIVE

To assess the hemostatic balance in patients with multiple coagulation disorders by using a thrombin generation assay.

METHOD

We performed conventional coagulation assays and a thrombin generation assay on samples from patients with congenital disorder of glycosylation. The thrombin generation assay was performed before and after activation of the protein C system by the addition of soluble thrombomodulin.

RESULTS

A total of 35 patients were included: 71% and 57% had low antithrombin and factor XI levels, respectively. Protein C and protein S levels were abnormally low in 29% and 26% of the patients, respectively, whereas only 11% displayed low factor IX levels. Under baseline conditions, the thrombin generation assay revealed a significantly higher endogenous thrombin potential and thrombin peak in patients, relative to controls. After spiking with thrombomodulin, we observed impaired involvement of the protein C system. Hence, 54% of patients displayed a hypercoagulant phenotype in vitro. All the patients with a history of stroke-like episodes or thrombosis displayed this hypercoagulant phenotype.

CONCLUSION

A thrombin generation assay revealed a hypercoagulant in vitro phenotype under baseline condition; this was accentuated by impaired involvement of the protein C system. This procoagulant phenotype may thus reflect the risk of severe vascular complications. Further research will have to determine whether the thrombin generation assay is predictive of vascular events.

International clinical guidelines for the management of phosphomannomutase 2-congenital disorders of glycosylation: Diagnosis, treatment and follow up

Phosphomannomutase 2 (PMM2-CDG) is the most common congenital disorder of N-glycosylation and is caused by a deficient PMM2 activity. The clinical presentation and the onset of PMM2-CDG vary among affected individuals ranging from a severe antenatal presentation with multisystem involvement to mild adulthood presentation limited to minor neurological involvement. Management of affected patients requires a multidisciplinary approach. In this article, a systematic review of the literature on PMM2-CDG was conducted by a group of international experts in different aspects of CDG. Our managment guidelines were initiated based on the available evidence-based data and experts' opinions. This guideline mainly addresses the clinical evaluation of each system/organ involved in PMM2-CDG, and the recommended management approach. It is the first systematic review of current practices in PMM2-CDG and the first guidelines aiming at establishing a practical approach to the recognition, diagnosis and management of PMM2-CDG patients.

Anesthetic management of a child with phosphomannomutase-2 congenital disorder of glycosylation (PMM2-CDG)

Background

Glycosylation is one of the major posttranslational modifications of proteins and it is essential for proteins to obtain normal biological functions. Congenital disorders of glycosylation (CDGs) are very rare genetic disorders that lack enzymes needed for glycosylation. Phosphomannomutase-2 (PMM2)-CDG is the most common type of CDG. CDGs can cause a wide variety of clinical symptoms in almost every organ system. Muscular hypotonia is often present in patients with CDGs and is one of the most notable problems for anesthetic management because the susceptibility to nondepolarizing neuromuscular blocking agents (NMBAs) in patients with CDGs is unknown.

Case presentation

The patient was a 17-month-old boy who weighed 6.5 kg and was 71 cm tall. He presented for strabismus surgery. He had muscular hypotonia, mental retardation, hepatic dysfunction, mild cerebellar hypoplasia, and some dysmorphic features including inverted nipples and abnormal subcutaneous fat distribution of the hips. Gene analysis revealed a compound heterozygous mutation in the gene encoding PMM2 and the patient was diagnosed as having PMM2-CDG. General anesthesia was performed with sevoflurane, nitrous oxide, and rocuronium. Neuromuscular monitoring was performed during anesthesia using train-of-four (TOF)-Watch^® (MSD, Japan). As postoperative analgesia, the surgeon performed sub-Tenon’s anesthesia. We did not use any intravenous analgesic. After completion of the operation, residual rocuronium was competed by administration of sugammadex. The patient gained consciousness and spontaneous breathing was established shortly thereafter, and the trachea was smoothly extubated. He was transported to an inpatient ward and was discharged to his home the next day without any complication.

Conclusions

We performed safe anesthetic management in a 17-month-old boy with PMM2-CDG using rocuronium under neuromuscular monitoring.

A patient with PMM2-CDG may show nearly normal susceptibility to nondepolarizing NMBAs.