GA1 can be defined as two clinical entities: GA-1 diagnosed at birth or pre-birth and managed through dietary restrictions, and GA-1 diagnosed after an encephalopathic crisis. A crisis may occur under both headings, but individuals diagnosed prior to a crisis can be managed to avoid most or all injury. GA1 without encephalopathic crisis[ edit ] Macrocephaly[ edit ] Babies with glutaric acidemia type 1 often are born with unusually large heads macrocephaly. Macrocephaly is amongst the earliest signs of GA1. It is thus important to investigate all cases of macrocephaly of unknown origins for GCDH deficiency,   given the importance of the early diagnosis of GA1.
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Imaging differential diagnosis Epidemiology Glutaric aciduria type 1 is a rare organic aciduria, with an estimated prevalence of 1 in , newborns 2.
It is inherited in an autosomal recessive manner, and hence consanguineous marriages are a risk factor. Clinical presentation Glutaric aciduria type 1 has a variable presentation, but typically, affected neonates are asymptomatic in the first few months of life 3, other than developing macrocephaly. They tend to present with an acute encephalopathy following concurrent infection or acute catabolic state e. Hence, the initial presentation may resemble viral encephalitis or ADEM.
Following the acute presentation, extrapyramidal symptoms develop which correlate, on imaging, with striatal involvement and subsequent necrosis 4. A subset of patients present with an insidious onset without episodes of acute deterioration 1, and others still present as adults with progressive encephalopathy, or are asymptomatic 3. A wide range of presentation may thus be encountered. Pathology Glutaric aciduria type I is caused by an inherited deficiency of the enzyme glutaryl-CoA dehydrogenase.
This leads to accumulation of glutaric acid and 3-hydroxyglutaric acid in the brain and body fluids, including urine hence the name glutaric aciduria. Type II glutaric aciduria is a different disease caused by unrelated enzyme deficiencies 5. Markers Routine blood, urine and CSF analysis for the metabolites mentioned above may be misleading, as excretion is only intermittent even during episodes of acute decompensation 3,6.
Imaging, therefore, has an important role to play in these situations. Genetics Definitive diagnosis of glutaric aciduria type 1 can be established by DNA-based analysis, looking for mutations in the GCDH gene on chromosome 19 1.
Radiographic features MRI is the modality of choice in the assessment of glutaric aciduria type 1. In clinically severely affected children, bilateral basal ganglia abnormalities are seen, with initial swelling that subsequently progresses to atrophy and necrosis. Other grey matter structures can be affected, e. Hyperintensity of the tegmental tracts along the fourth ventricle floor has also been described. Delay in myelination is a further finding in severely affected infants.
The above changes are not necessarily seen in less severely affected children. Common features in both groups of patients are macrocephaly, expansion of subarachnoid convexity spaces, and wide CSF spaces anterior to the temporal poles and in the Sylvian fissures.
Whether these wide CSF spaces represent arachnoid cysts rather than atrophy and under-opercularisation of the Sylvian fissures, remains unresolved. With the expansion of convexity subarachnoid spaces, the coursing bridging veins are susceptible to rupture with only minor trauma, and these patients may present with subdural hemorrhages.
In this context, the radiologist needs to be familiar with the imaging findings of glutaric aciduria type I so that an erroneous diagnosis of non-accidental injury is not made. The findings described above are not by themselves specific, but the combination of these findings in a macrocephalic child with extrapyramidal symptoms are at least highly suggestive, if not pathognomonic Signal characteristics:.
Glutaric acidemia type I
Imaging differential diagnosis Epidemiology Glutaric aciduria type 1 is a rare organic aciduria, with an estimated prevalence of 1 in , newborns 2. It is inherited in an autosomal recessive manner, and hence consanguineous marriages are a risk factor. Clinical presentation Glutaric aciduria type 1 has a variable presentation, but typically, affected neonates are asymptomatic in the first few months of life 3, other than developing macrocephaly. They tend to present with an acute encephalopathy following concurrent infection or acute catabolic state e.
Aciduria glutárica tipo 1
GA1 is included on the newborn screening panel in most countries. However, if treatment is not started early or is not followed properly, the severity of symptoms varies from person to person. Symptoms usually begin in infancy or early childhood, but sometimes symptoms begin in adolescence or adulthood. In rare cases, a person with GA1 does not develop any symptoms, even if not treated.
Aciduria glutárica tipo I
Description Glutaric acidemia type I also called glutaric aciduria type I is an inherited disorder in which the body is unable to process certain proteins properly. It is classified as an organic acid disorder, which is a condition that leads to an abnormal buildup of particular acids known as organic acids. Abnormal levels of organic acids in the blood organic acidemia , urine organic aciduria , and tissues can be toxic and can cause serious health problems. People with glutaric acidemia type I have inadequate levels of an enzyme that helps break down the amino acids lysine, hydroxylysine, and tryptophan, which are building blocks of protein.
Acidemia Glutarica tipo I