Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.4.2.8 (phosphomannomutase)
 238 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Congenital disorders of glycosylation (CDG) are a group of metabolic disorders with multisystemic involvement characterized by abnormalities in the synthesis of N-linked oligosaccharides. The most common form, CDG-Ia, resulting from mutations in the gene encoding the enzyme phosphomannomutase (PMM2), manifests with severe abnormalities in psychomotor development, dysmorphic features and visceral involvement. While this disorder is panethnic, we present the first cases of CDG-Ia identified in an African American family with two affected sisters. The proband had failure to thrive in infancy, hypotonia, ataxia, cerebellar hypoplasia and developmental delay. On examination, she also exhibited strabismus, inverted nipples and an atypical perineal fat distribution, all features characteristic of CDG-Ia. Direct sequencing demonstrated that the patient had a unique genotype, T237M/c.565-571 delAGAGAT insGTGGATTTCC. The novel deletion-insertion mutation, which was confirmed by subcloning and sequencing of each allele, introduces a stop codon 11 amino acids downstream from the site of the deletion. The presence of this deletion-insertion mutation at cDNA position 565 suggests that this site in the PMM2 gene may be a hotspot for chromosomal breakage.
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PMID:A deletion-insertion mutation in the phosphomannomutase 2 gene in an African American patient with congenital disorders of glycosylation-Ia. 1189 94

Carbohydrate deficient glycoprotein syndromes (CDG) are inherited multisystem disorders characterized by the abnormal glycosylation of a number of serum glycoproteins. CDG-Ia results from deficiency of phosphomannomutase that catalyzes the conversion of mannose-6-phosphate to mannose-1-phosphate in the cytosol. We report a case of CDG-Ia in an 11-month-old girl with developmental delay, failure to thrive, inverted nipples and abnormal fat pads. The abnormal pattern of transferrin glycosylation and phosphomannomutase activity assay confirmed the diagnosis of CDG type Ia. Unfortunately, an efficient treatment is still not available for CDG type Ia patients. This is the first report of a Taiwanese patient with this syndrome.
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PMID:Carbohydrate deficient glycoprotein syndrome type Ia. 1536 47

CDG Ia (phosphomannomutase deficiency) has a wide clinical spectrum with the most severe affected patients having multisystemic disease in addition to severe nervous system involvement. We report a patient with CDG Ia and an intermediate phenotype due to mild neurological impairment and borderline cognitive abilities despite the occurrence of typical extraneurological symptoms. These included liver involvement, coagulopathy and failure to thrive with enteropathy. Genotype analyses showed that he was compound heterozygous for T237R/C241S mutations. This observation underlines that the CDG Ia clinical spectrum may include intraindividual variability that might reflect different degrees of glycosylation abnormalities among distinct body compartments. CDG Ia should be considered in cases of unexplained liver involvement and/or enteropathy in patients with mild developmental delay and subtle neurological signs.
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PMID:Borderline mental development in a congenital disorder of glycosylation (CDG) type Ia patient with multisystemic involvement (intermediate phenotype). 1718 15

Congenital disorder of glycosylation Ia (CDG-Ia) is a metabolic disease with a broad spectrum of clinical signs, including recently described mild phenotypes. Our aim was to describe the clinical presentation and follow-up of eight CDG-Ia patients highlighting atypical features and aspects of evolution of the disease. CDG diagnosis was confirmed by enzymatic analysis of phosphomannomutase (PMM2) and molecular studies of the PMM2 gene. Four neonates presented with cerebral haemorrhage (1), failure to thrive (2) and non-immune hydrops (1) and a fatal course to death (2); pathological examination of the brain in one case revealed olivopontocerebellar atrophy of prenatal origin. During infancy failure to thrive, coagulopathy and hepatopathy were the most significant causes of morbidity, but these disappeared after the first years of life in most patients. Three patients are currently in their 20s; they present mental retardation and severe motor impairment but no acute decompensations were noticed after the first decade of life. They do not present spinal or thoracic deformities otherwise observed in patients from northern countries. A 10-year-old patient who manifested gastrointestinal dysfunction in early childhood showed normal neurodevelopment. Mutation analysis of the PMM2 gene showed great variability, with all patients being compound heterozygous for two different mutations. Long-term evolution in our patients indicates that CDG-Ia is a stable systemic and neurological condition after the first decade of life. The diverse phenotypes and atypical manifestations in our series may be due to their genetic heterogeneity.
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PMID:Long-term evolution of eight Spanish patients with CDG type Ia: typical and atypical manifestations. 1894 42

We describe three patients with congenital disorder of glycosylation (CDG) type Ia, all of whom had persistent hyperinsulinaemic hypoglycaemia responding to diazoxide therapy as a common feature. The first patient, an infant girl, presented with recurrent vomiting, failure to thrive, liver impairment, hypothyroidism and a pericardial effusion. The second patient, also female, had a milder disease with single organ involvement, presenting as isolated hyperinsulinaemic hypoglycaemia, not associated with any cognitive impairment. The third patient, a boy presented with multi-organ manifestations including congenital hypothyroidism, persistent hyperinsulinaemic hypoglycaemia, coagulopathy, olivopontocerebellar hypoplasia and recurrent pancreatitis. All three patients had a type 1 serum transferrin isoform pattern, and were subsequently found to have low phosphomannomutase activity, confirming the diagnosis of CDG type Ia. Our findings emphasize that CDG should be considered as a differential diagnosis in patients with persistent hyperinsulinaemic hypoglycaemia and that it may even occasionally be the leading symptom in CDG Ia.
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PMID:Congenital disorder of glycosylation type Ia: heterogeneity in the clinical presentation from multivisceral failure to hyperinsulinaemic hypoglycaemia as leading symptoms in three infants with phosphomannomutase deficiency. 1939 70

Congenital disorders of glycosylation (CDG) are a group of metabolic disorders caused by deficient protein glycosylation. PMM2-CDG, the most common CDG, is caused by phosphomannomutase (PMM) deficiency. Clinical symptoms often include neurological involvement in addition to dysmorphic features, failure to thrive, cardiac failure, renal, and endocrine abnormalities. To our knowledge, lymphatic edema in CDG has not been reported. We present two cases of lymphatic edema in PMM2-CDG patients. The first patient was noted to have a larger right leg circumference at two years. Ultrasound investigations did not reveal any obvious vascular or lymphatic malformation. The swelling increased in size over time. At 12 years, lymphoscintigraphy revealed decreased lymphatic draining in both legs, which was more profound in the right leg. The second patient was treated for pulmonary stenosis at age 2 months. Postoperative, the patient suffered from protein-losing enteropathy, hypothyroidism, recurrent bacterial infections, and bilateral lymphatic edema. General condition improved after thyroxin treatment and albumin infusions; however, the bilateral pedal and leg edema remained unresolved. Contrast studies of the lymphatic system showed bilateral hypoplasia distal to the knees. Although both children had secondary factors worsening lymphatic edema in PMM2-CDG, hypoalbuminemia, recurrent infections, cardiac failure, and endocrine abnormalities could not fully explain the clinical features. The additional factors were treated successfully but the therapy did not resolve the lymphatic edema. Based on the abnormal imaging studies of the lymphatic system, we propose that lymphatic vessel hypoplasia is the major cause for lymphatic edema in our patients with PMM2-CDG.
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PMID:Lymphatic edema in congenital disorders of glycosylation. 2343 Sep 5