Congenital disorder of glycosylation type 1b. Experience with mannose treatment

Congenital disorders of glycosylation (CDG) are recessively inherited multisystemic disorders resulting from several genetic defects affecting the assembly, transfer or processing of oligosaccharides onto proteins and other glycoconjugates. CDG type Ib is due to a deficiency of phosphomannose isomerase (PMI) encoded by the MPI gene. PMI catalyzes the interconversion of fructose-6-P and mannose-6-P. The clinical phenotype is characterized by gastro-intestinal and hepatic symptoms. In contrast to most CDG patients, there is no neurological affectation. It's a mannose treatable disorder. We report the first recognised case of CDG Ib in Spain. He presented at 6 months with hypoglycaemia, failure to thrive and hypertransaminasaemia. He subsequently developed an enteropathy with subtotal villous atrophy on biopsy. The %CDT was very high and he presented with a type 1 pattern in transferrin isoelectric focusing. PMI activity in fibroblasts was very deficient. Mutations in MPI gene at R219Q and R56fs were found. Clinical and biochemical parameters normalised after treatment with mannose 1 g/kg/day in 5 doses. CDG Ib should be considered in patients with hypoglycaemia, liver disease, enteropathy and hypercoagulability, in the absence of other common causes, and particularly if some of them are combined.     

Medium-chain acyl-CoA dehydrogenase deficiency does not correlate with apparent life-threatening events and the sudden infant death syndrome: results from phenylpropionate loading tests and DNA analysis

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inherited disorder of fatty acid metabolism and typically presents in early childhood as potentially fatal hypoketotic, hypoglycaemic crisis often associated with Reye-like symptoms. Re-investigations of cases of sudden infant death syndrome (SIDS) have revealed in some instances a deficiency of MCAD, suggesting that this metabolic disorder may lead to sudden infant death without prior clinical symptoms. In the present study, we examined 142 infants who had suffered from an apparent life-threatening event (ALTE) or were otherwise considered at risk for SIDS for MCAD deficiency by phenylpropionate loading. In no case excretion of phenylpropionylglycine, the hallmark of MCAD deficiency, was increased. In contrast, 3 out of 55 children with symptoms of metabolic disorders showed increased phenylpropionylglycine excretion, and in all three cases MCAD deficiency was confirmed by DNA analysis. In addition, we investigated 142 cases of sudden unexplained child death and 100 control subjects for the A985G mutation in the MCAD gene which is associated with about 98% of enzyme deficiencies. We found one case of heterozygosity each in the patient and control group. Our data indicate that MCAD deficiency is not a major cause of ALTE and, in agreement with results from similar studies in other countries, its frequency is not increased in children who died of SIDS.     

Hereditary heterozygote factor VII deficiency]

Hereditary Factor VII deficiency is one of the rare congenital coagulopathies. Prolonged prothrombin time (PT) with normal partial prothrombin time (PTT) may be an indicator for Factor VII deficiency. A family with hereditary heterozygous Factor VII deficiency is presented in whom no symptoms of a bleeding disorder were clinically detectable. A discussion of the therapeutic options follows.     

Two unusual clinical and radiological presentations of biotinidase deficiency

Biotinidase deficiency is due to a defect in recycling of biotin and is a treatable autosomal recessive inherited disorder.We describe two cases with unusual presenting symptoms and rarely described MRI findings.We propose that the diagnosis of biotinidase deficiency should be considered when there are symmetrical MRI changes in the medial thalamus, dorsal brainstem, medulla and spinal cord as in our two cases.As long as there isn't newborn screening for biotinidase deficiency in the UK; increased awareness of this disorder and recognition of biotinidase deficiency as a cause of bilateral symmetrical MRI patterns similar to our patients, would facilitate early diagnosis and prevent many of the devastating neurological sequelae associated with missing the condition.     

Mutations causing profound biotinidase deficiency in children ascertained by newborn screening in the United States occur at different frequencies than in symptomatic children.

Biotinidase deficiency is an autosomal recessive disorder of biotin metabolism that can lead to varying degrees of neurologic and cutaneous symptoms when untreated. Because this disorder meets the criteria for newborn screening, many states and countries perform this testing. Because newborn screening should result in complete ascertainment of mutations causing profound biotinidase deficiency (less than 10% of mean normal serum activity), we compared the mutations in a group of 59 children with profound biotinidase deficiency who were identified by newborn screening in the United States with 33 children ascertained by exhibiting symptoms. Of the 40 total mutations identified among the two populations, four mutations comprise 59% of the disease alleles studied. Two of these mutations occur in both populations, but in the symptomatic group at a significantly greater frequency. The other two common mutations occur only in the newborn screening group. Because two common mutations do not occur in the symptomatic population, it is possible that individuals with these mutations either develop mild or no symptoms if left untreated. However, inasmuch as biotin treatment is inexpensive and innocuous, it is still recommended that all children with profound biotinidase deficiency be treated.     

Medium-chain acyl-CoA dehydrogenase deficiency: Molecular aspects

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is an autosomal recessive disorder which is known to cause Reye-like syndrome in children and sudden infant death. A point mutation of lysine329-to-glutamic acid329 substitution in the MCAD gene was recently identified as the most common mutation in patients with MCAD deficiency. This mutation is responsible for about 90% of mutant MCAD alleles in Caucasians. Patients with this type of mutation have a variety of symptoms, indicating that the clinical heterogeneity of MCAD deficiency may not be caused entirely by genetic heterogeneity. Screening for the mutation among newborns in England, Australia, and United States of America indicates the prevalence of carriers to be 1 in 40-107, suggesting the high incidence of the mutation. Since presymptomatic diagnosis and appropriate dietary management are important in MCAD deficiency to prevent life-threatening complications, the relatively high incidence of this disorder may warrant population screening. The most common MCAD mutation can now be detected by DNA diagnostic methods using Guthrie cards. This makes it possible to screen a population efficiently for this potentially fatal disorder.     

Intracranial Hemorrhage as the First Manifestation of Severe Congenital Factor X Deficiency in a 20‐Month‐Old Male: Case Report and Review of the Literature

Factor X deficiency (FXD) is a rare bleeding disorder, which can result in severe bleeding symptoms such as intracranial hemorrhage (ICH). The most common bleeding symptoms are epistaxis and gum bleeding. ICH is reported in 9–26% of all patients with FXD, mostly during the first month of life. Here, we present a rare case of a male presenting with ICH at the age of 20 months as the first manifestation of FXD. Secondary prophylaxis with factor X substitution once weekly prevented further bleeding.     

Defekt der langkettigen 3-Hydroxy-Acyl-CoA-Dehydrogenase—LCHAD-Defekt

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency is a rare inborn disorder of mitochondrial fatty acid β-oxidation. Clinical manifestations include acute symptoms such as hypoketotic hypoglycemia with hepatopathy and encephalopathy and chronic symptoms such as myopathy, cardiomyopathy, neuropathy, and retinopathy. More than 80% of patients with acute manifestations of LCHAD deficiency will die during the first 2 years of life. Fatty acid oxidation defects can now be diagnosed during the initial days of life in the presymptomatic state by newborn screening with tandem mass spectrometry. Screening of 630,000 newborns detected 9 patients with LCHAD defect (a high incidence of 1:30,000 in the north-western part of Germany). We report on the clinical course of two patients with LCHAD defect who were diagnosed by newborn screening during their first 2 years of life. The development of characteristic symptoms in both patients could not be prevented. However, with early and specific therapy both patients showed normal development at the age of 24 months. The hope is that early identification of such patients through newborn screening may improve the prognosis of patients with this disorder.     

Rat heart perfusion as model system for enzyme replacement therapy in glycogenosis type II

Cardiac failure and skeletal muscle weakness are the main clinical features of glycogenosis type II, a lysosomal storage disorder caused by acid alpha-glucosidase deficiency. In our study, we have investigated in a rat heart perfusion-recirculation system whether acid alpha-glucosidase can be taken up from the vascular system into cardiomyocytes. When rat hearts were perfused with mannose 6-phosphate-containing acid alpha-glucosidase purified from bovine testis, a 3- to 4-fold increase of enzyme activity was obtained. Perfusion with human placental acid alpha-glucosidase not containing the mannose 6-phosphate recognition marker did not have such an effect. The presence of bovine testis acid alpha-glucosidase in heart tissue was demonstrated by immunoblotting. Immunocytochemistry provides evidence for uptake of the exogenous enzyme in lysosomes of the cardiomyocytes. The relevance of these findings for enzyme therapy in glycogenosis type II is discussed.     

Kelley-Seegmiller syndrome

BACKGROUND: Hypoxanthinguanin-phosphoribosyltransferase (HPRT) deficiency, an x-linked inherited disease can cause two presentations: A complete deficiency (Lesch-Nyhan syndrome) accompanies with grave renal and neurological symptoms. A second form is the partial enzyme deficiency (Kelley-Seegmiller syndrome). PATIENT: We present a thirteen year old boy with relapsing hyperuricemia and hypercreatininemia. In the framework of postoperative renal insufficiency the diagnose of a Kelley-Seegmiller syndrome was elaborated. RESULT: About 25% of patients with Kelley-Seegmiller syndrome present mild neurological symptoms but never with self-destructive behavior. Pathophysiological an increased de novo purinsynthesis is present. Therefore, it comes to an overproduction of urine acid. Urolithiasis is one clinical manifestation. CONCLUSION: Relapsing urolithiasis and renal insufficiency has to be worked up. In the differential diagnosis a disorder of purine metabolism has to be discussed.     

Treatment of glutaryl-CoA dehydrogenase deficiency (glutaric aciduria). Experience with diet, riboflavin, and GABA analogue.

The autosomal recessive inherited disorder glutaryl-CoA dehydrogenase deficiency (glutaric aciduria) runs a progressive course with severe choreoathetosis and dystonia, eventually leading to total helplessness and early death. Theree patients were observed during therapeutic trials with a protein-low diet, riboflavin and GABA analogue. Diet and riboflavin had a slight-to-moderate effect on the clinical symptoms; the excretion of glutaric acid and 2-amino-adipic acid decreased considerably during treatment. Regression of neurologic symptoms was observed during treatment with GABA analogue. It is concluded that the patients should be treated as early as possible with protein-low diet, riboflavin, and GABA analogue.     

Long chain 3-hydroxyacyl-coA dehydrogenase deficiency, asociation with HELLP and magnetic resonance spectroscopy findings

LCHAD deficiency is a disorder of fatty acid beta oxidation. The most common clinical presentation includes disorders of consciousness, hypoglycemia and liver dysfunction triggered by prolonged fasting or infection. Once a metabolic crisis is triggered, there is a high mortality. HELLP syndrome and acute fatty liver failure of pregnancy (AFLP) are disorders of the third trimester of pregnancy. These diseases have been associated during pregnancy with hereditary defects of beta-oxidation in the fetus. We report a case of beta-oxidation disorder (LCHAD deficiency) associated with maternal HELLP. We described a peak of lipid and lactic on magnetic resonance spectroscopic of this patient. The investigation of these beta-oxidation disorders at birth, with a history of maternal HELLP, allows the diagnosis of the disease prior to developing symptoms.     

Outcome of medium chain acyl-CoA dehydrogenase deficiency after diagnosis.

BACKGROUND: Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inborn error of fatty acid metabolism. Undiagnosed, it has a mortality rate of 20-25%. Neonatal screening for the disorder is now possible but it is not known whether this would alter the prognosis. OBJECTIVE: To investigate the outcome of MCAD deficiency after the diagnosis has been established. METHOD: All patients with a proved diagnosis of MCAD deficiency attending one centre in a four year period were reviewed. RESULTS: Forty one patients were identified. Follow up was for a median of 6.7 years (range, 9 months to 14 years). Nearly half of the patients were admitted to hospital with symptoms characteristic of MCAD deficiency before the correct diagnosis was made. After diagnosis, two patients were admitted to hospital with severe encephalopathy but there were no additional deaths or appreciable morbidity. There was a high incidence (about one fifth) of previous sibling deaths among the cohort. CONCLUSIONS: Undiagnosed, MCAD deficiency results in considerable mortality and morbidity. However, current management improves outcome, supporting the view that the disorder should be included in newborn screening programmes.     

RECURRENT THROMBO-EMBOLISM IN A CHILD WITH A CONGENITAL DISORDER OF GLYCOSYLATION (CDG) TYPE IB AND TREATMENT WITH MANNOSE

Thrombosis is a multifactorial disorder. Congenital disorders of glycosylation (CDG) are one of the known risk factors for its occurrence. These disorders result in glycosylation defects of glycoproteins, including those of the (anti-)coagulation system. CDG-Ib can specifically be treated with mannose, as illustrated by the case of a 4-year-old girl in whom deep venous thrombosis was the presenting symptom after a common viral infection. The diagnosis was made after recurrent episodes of thrombo-embolism and consumptive coagulopathy. After treatment with mannose no such episodes recurred. The pathophysiology of CDG as a risk factor for thrombotic disease is discussed.     

Two novel glucose-6-phosphate dehydrogenase variants found in newborn mass-screening for galactosaemia

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked recessive disorder in which haemolytic anaemia is the major symptom. The Beutler spot test employed in mass-screening for galactosaemia in newborns requires several intrinsic erythrocyte enzymes such as G6PD for its reaction and can theoretically detect G6PD deficiency apart from galactose-1-phosphate uridyltransferase deficiency. In this study, we detected two patients with G6PD deficiency using the quantitative Beutler test which was recently developed in our laboratory. Both patients lacked erythrocyte G6PD activity but exhibited no clinical symptoms. Molecular analysis in patients 1 and 2 revealed two novel missense mutations of C853T causing R285C and A1220C causing K407T, respectively. Molecular rather than enzymatic analysis was required in familial studies to detect and diagnose the carrier state. To date these patients have avoided oxidant stress and haemolytic diatheses have not been induced. CONCLUSION: Our results indicate that the quantitative Beutler test can detect glucose-6-phosphate dehydrogenase deficiency of class 1 and 2 and is therefore useful for early intervention and prevention of haemolytic diathesis in patients with this disorder.     

A novel presentation of familial glucocorticoid deficiency (FGD) and current literature review

Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disorder, which manifests as isolated glucocorticoid deficiency with normal mineralocorticoid function. The disease is secondary to ACTH unresponsiveness, with low serum cortisol concentrations in the presence of markedly elevated ACTH levels. Approximately 40% of patients with FGD have an identifiable mutation in the ACTH receptor gene. The typical presentation of FGD includes recurrent hypoglycemia, failure to thrive, and hyperpigmentation prior to 5 years of age. Patients with point mutations in the ACTH receptor gene are noted to be of tall stature. We report a patient with an atypical initial presentation of this condition. Our patient differed from the typical presentation by having late age of onset, short stature, and few symptoms of FGD. Sequence analysis of the ACTH receptor gene showed compound heterozygosity, with two previously reported mutations: S74I and T159K. Her unique presentation further illustrates the phenotypic heterogeneity of this disorder in light of reported mutations.     

琥珀酸半醛脱氢酶缺陷病

琥珀酸半醛脱氢酶（SSADH）缺陷病是一种少见的常染色体隐性遗传病。本研究总结3例SSADH缺陷病患儿的临床资料并复习相关文献。3例患儿均为婴幼儿,主要表现为智力运动、语言发育落后,抽搐和肌张力低下。3例患儿脑电图均表现异常;2例脑MRI检查异常,表现为大脑脚对称性长T2高信号和基底节损害;3例尿液的气相色谱-质谱（GC-MS）分析均显示4-羟基丁酸增高,根据临床表现及尿液GC-MS分析确诊为SSADH缺陷病。对不明原因发育迟缓、智力运动障碍和癫癎的患儿应早期进行尿液有机酸分析,对明确诊断具有重要意义。     

Remarks on a clinical case of partial carbamyl phosphate synthetase deficiency

A preliminary undiagnosed case of partial carbamyl-phosphate-synthetase deficiency in a 14 year old patient is described. This extremely rare metabolic disorder is unlikely to produce clinical symptoms at such an advanced age. Details are given of the clinical picture, the diagnosis (by liver biopsy and post mortem liver examination) and the attempts at treatment.     

Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency: A severe fatty acid oxidation disorder

3-Hydroxyacyl-CoA dehydrogenase deficiency is a newly recognised fatty acid oxidation disorder with a usually fatal outcome. We present a further patient who presented with hypoketotic hypoglycaemia, hepatopathy, secondary carnitine deficiency and increased plasma long-chain acylcarnitines. 3-Hydroxydicarboxylic aciduria was present and the diagnosis confirmed in cultured skin fibroblasts. Our patient is compared with those reported in the literature with respect to clinical symptoms, differential diagnosis and possible therapeutic regimens.     

Outcome of medium chain acyl-CoA dehydrogenase deficiency after diagnosis

BACKGROUND—Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inborn error of fatty acid metabolism. Undiagnosed, it has a mortality rate of 20-25%. Neonatal screening for the disorder is now possible but it is not known whether this would alter the prognosis.OBJECTIVE—To investigate the outcome of MCAD deficiency after the diagnosis has been established.METHOD—All patients with a proved diagnosis of MCAD deficiency attending one centre in a four year period were reviewed.RESULTS—Forty one patients were identified. Follow up was for a median of 6.7 years (range, 9 months to 14 years). Nearly half of the patients were admitted to hospital with symptoms characteristic of MCAD deficiency before the correct diagnosis was made. After diagnosis, two patients were admitted to hospital with severe encephalopathy but there were no additional deaths or appreciable morbidity. There was a high incidence (about one fifth) of previous sibling deaths among the cohort.CONCLUSIONS—Undiagnosed, MCAD deficiency results in considerable mortality and morbidity. However, current management improves outcome, supporting the view that the disorder should be included in newborn screening programmes.