The majority of children with intermediate MSUD are diagnosed between the ages of 5 months and 7 years. Symptoms associated with classic MSUD also appear in intermediate MSUD. Intermittent MSUD
Contrary to classic and intermediate MSUD, intermittent MSUD individuals will have normal growth and intellectual development. Symptoms of lethargy and characterized odor of maple syrup will occur when the individual experiences stress, does not eat, or develops an infection. Metabolic crisis leading to seizures, coma, and brain damage is still a possibility. Thiamine-response MSUD
Symptoms associated with thiamine-response MSUD are similar to intermediate MSUD. Newborns rarely present with symptoms. Later onset
The symptoms of MSUD may also present later depending on the severity of the disease. Untreated in older individuals, and during times of metabolic crisis, symptoms of the condition include uncharacteristically inappropriate, extreme or erratic behaviour and moods, hallucinations, lack of appetite, weight loss, anemia, diarrhea, vomiting, dehydration, lethargy, oscillating hypertonia and hypotonia, ataxia, seizures, hypoglycaemia, ketoacidosis, opisthotonus, pancreatitis, rapid neurological decline, and coma. Death from cerebral edema will likely occur if there is no treatment. Additionally, MSUD patients experience an abnormal course of diseases in simple infections that can lead to permanent damage. Causes
Mutations in the following genes cause maple syrup urine disease:

BCKDHA (OMIM: 608348)
BCKDHB (OMIM: 248611)
DBT (OMIM: 248610)
DLD (OMIM: 238331)These four genes produce proteins that work together as the branched-chain alpha-keto acid dehydrogenase complex. The complex is essential for breaking down the amino acids leucine, isoleucine, and valine.
Profoundly degranulated eosinophils may also be present, as may micro-abscesses and an expansion of the basal layer.Patients found to have signs of EoE on endoscopy should undergo an empiric 8-week trial of high-dose proton pump inhibitor therapy (twice daily) before repeat endoscopy in order to rule out GERD. Although endoscopic findings are helpful in identifying patients with EoE, they are not diagnostic of the disease if the patient has no clinical symptoms. Esophageal mucosal biopsy
Currently, endoscopic mucosal biopsy remains the most important diagnostic test for EoE, and is required to confirm the diagnosis. Biopsy specimens from both the proximal/mid and distal esophagus should be obtained regardless of the gross appearance of the mucosa. Specimens should also be obtained from areas revealing endoscopic abnormalities. At least four biopsies are required to obtain adequate sensitivity for the detection of EoE. A definitive diagnosis of EoE is based on the presence of at least 15 eosinophils/HPF in the esophageal biopsies of patients despite treatment with high-dose PPI. GERD can increase eosinophilic infiltration in the distal esophagus, however, eosinophils associated with GERD generally occur at a lower density (i.e. < 15/HPF). Allergy assessment
A thorough personal and family history of other atopic conditions is recommended in all patients with EoE. Testing for allergic sensitization may be considered using skin prick testing or blood testing for allergen-specific IgE. This is particularly important for the 10–20% of EoE patients who also have symptoms of immediate IgE-mediated food allergy.