Characterization of the SRD5A3-CDG Clinical Spectrum

Abstract We aimed to characterize the clinical spectrum of patients diagnosed with SRD5A3-CDG, a subtype of congenital disorders of glycosylation (CDG) due to variants in the steroid 5a-reductase type 3 (SRD5A3) gene. It presents with multi-systemic involvement including neurological disability, dermatologic abnormalities, and ophthalmological defects. We conducted a cross-sectional study of children (n=6, ages 4-16 years) with a confirmed diagnosis of SRD5A3-CDG (c.57G>A, p.W19X). Families completed a detailed medical history questionnaire, two quality of life measures, and an adaptive behavior scale. Prevalent clinical features in our cohort included visual impairment (6/6), developmental delay (6/6), nystagmus (5/6), retinal dystrophy (4/6), and hypotonia (3/6). The Vineland Adaptive Behavior Scales demonstrated deficits across all functional domains (Composite Mean 36.17 ± 26.88), although one child did not show significant deficits. The QI-Disability Form demonstrated a mean total score of 64.8 (±12.7), and the PedsQL-Family Impact Module demonstrated a mean total score of 56.5 (±31.5). Vineland composite scores did not correlate with levels of disability captured by the QI-Disability Form (Pearson Correlation range -0.63 to +0.69, p>0.05 on all subscales). Ultimately, despite genotypic homogeneity, there is notable variability in adaptive functioning and quality of life among affected children that does not correlate with age.

Advances in the diagnosis and treatment of phosphomannomutase 2 deficiency / 中国当代儿科杂志

Phosphomannomutase 2 deficiency is the most common form of N-glycosylation disorders and is also known as phosphomannomutase 2-congenital disorder of glycosylation (PMM2-CDG). It is an autosomal recessive disease with multi-system involvements and is caused by mutations in the PMM2 gene (OMIM: 601785), with varying severities in individuals. At present, there is still no specific therapy for PMM2-CDG, and early identification, early diagnosis, and early treatment can effectively prolong the life span of pediatric patients. This article reviews the advances in the diagnosis and treatment of PMM2-CDG.

Congenital disorder of glycosylation caused by de novo variant of SLC35A2 gene: a case report / 中华神经科杂志

Congenital disorder of glycosylation (CDG) is a group of genetic metabolic diseases involving multiple organs. A case of CDG caused by SLC35A2 gene mutation was diagnosed. The clinical characteristics included spasms, developmental retardation and multiple malformations. Video-electroencephalogram showed dysrhythmia. A de novo heterozygous missense mutation of SLC35A2 gene was detected by whole exome sequencing: c.844G>A (p.Gly282Arg). It was predicted to be likely pathogenic according to American College of Medical Genetics and Genomics guidelines which had not been reported in China.

Case report of congenital disorder of glycosylation type Ia combined with dilated cardiomyopathy / 中华实用儿科临床杂志

Clinical data and follow-up of a case of congenital disorder of glycosylation type Ia (CDG-Ia) combined with dilated cardiomyopathy admitted to the Department of Cardiology, Children′s Hospital of Nanjing Medical University were analyzed retrospectively.The 5-year-old female patient was admitted in December 2016 due to recu-rrent shortness of breath for 2 months.Clinical symptoms and signs included repeated attacks of shortness of breath, physical retardation, malnutrition, binocular esotropia, multiple episodes of hypoglycemia, hepatosplenomegaly, hypotonia and other multi-system damages.Cardiac echocardiography suggested the feature of dilated cardiomyopathy, including the significant enlargement of the left ventricle, and decreased systolic function.Genetic testing revealed a compound heterozygous mutation in the PMM2 gene, and as a result, the patient was diagnosed as CDG-Ia.The patient′s condition improved after symptomatic treatments such as Cedilanid, Dopamine, Dobutamine, Furosemide, as well as support treatments like myocardium nutrition, blood sugar maintenance, liver protection, etc.After discharge, the patient was given oral Digoxin, Betaloc, Captopril and diuretics, and hypoglycemia-controlling agents.The patient was followed up every 3-6 months.After more than 2 years of follow-up, the heart function and heart enlargement gradually returned to normal.During the Corona Virus Disease 2019 outbreak, self-withdrawal continued for 2 months.Re-examinations showed decreased cardiac function and enlarged left ventricle again.Medications were resumed again, and the patient was followed up closely.This case report suggested that CDG-Ia may be associated with dilated cardiomyopathy, and the cardiac phenotype may be improved by symptomatic supportive treatment.

Prenatal presentation of a rare genetic disorder: a clinical, autopsy and molecular correlation

Walker Warburg syndrome (WWS) lies at the severe end of the spectrum of the congenital muscular dystrophies. WWS is a congenital disorder of the O-glycosylation that disrupts in the post-translation modification of dystroglycan proteins. WWS is characterized by the involvement of the central nervous system and rarely by multisystem involvement. Next-generation sequencing discovered that multiple genes are associated with this disorder. FKTN is the rarest cause of WWS. We describe a clinical-autopsy report of a molecularly- confirmed WWS case presenting with ventriculomegaly, agenesis of the corpus callosum with a novel phenotype of Dandy-Walker malformation and unilateral multi-cystic kidney. The whole-exome sequencing confirmed a homozygous variant (c.411C>A) in the FKTN gene with a premature termination codon. This case emphasizes the importance of detailed postnatal phenotyping through an autopsy in any pregnancy with antenatally identified malformations. Obstetricians, pediatricians as well as fetal medicine experts need to counsel the parents and focus on preserving the appropriate sample for genetic testing. WWS, though rare deserves testing especially in the presence of positive family history. Dandy-Walker malformation is a novel feature and expands the phenotypic spectrum.

Congenital disorder of glycosylation type 1a:a case report / 临床儿科杂志

Objective To explore the clinical features, diagnosis, and treatment of congenital disorder of glycosylation type 1a (CDG-Ⅰa), a rare inherited metabolic disease. Methods The clinical data and the gene detection results of one case of CDG-Ia which was discovered because the case had encephalopathy and hepatopathy were retrospectively analyzed. The related literatures were reviewed. Results Male infant suffered with face and trunk rash, motor development retardation, malnutrition, cheek fat plump, low limbs muscle tone, and bilateral crater nipple at 3 months old. Abnormal liver function and mild renal impairment were found after examination. The development quotient was low. Head MRI showed that bilateral frontal and temporal sulcus widening, and cerebellar atrophy. Urinary organic acids, amino acids, carnitine, and biotin activities were normal. Gene sequencing revealed that there were two heterozygous mutations, c.430T>C (p.F144L) and c.713G>C (p.R238P), in the PMM2 gene. The diagnosis of CDG-Ⅰa was confirmed. Both of the infant's parents were healthy, and each of them carries a pathogenic mutation. The infant had an elder brother who had mental disorder and died for liver and kidney function damage and hydronephrosis at 8 months old. Conclusion CDG-Ⅰa is an autosomal recessive disease. For infants with unexplained multiple organ damage, especially combined with intelligent and motor development retardations, strabismus, nipple retraction, and cerebellar atrophy, the possibility of CDG-Ⅰa should be considered. Gene detection of PMM2 can help the diagnosis.