Since the etiology is unconfirmed, diagnosis is generally accomplished when there is<unk>  present within 24–36 hours of birth and urea cycle defects can be excluded. Organic acidemias and other metabolic errors must also be excluded. The diagnostic criteria for<unk>  is ammonia blood levels higher than 35 μmol/L. This is accomplished by observing urine ketones, organic acids, enzyme levels and activities, and plasma and urine amino acids. Mild Transient<unk>  is diagnosed when ammonia levels are between 40-50 μM, lasts for about 6–8 weeks, and has no related neurological problems. Severe Transient<unk>  is diagnosed when ammonia levels are above 50 μM up to as much as 4000 μM. Severe Transient<unk>  causes neurological problems as ammonia levels in the brain are too high, which can cause infant hyptotonia as well as neonatal seizures. Severe Transient<unk>  can also cause respiratory distress syndrome. Chest x-rays may resemble hyaline membrane disease. Differentiating between UCED and THAN A study was done by Hudak to find the differences between<unk>  (THAN) and urea cycle enzyme deficiency(UCED) on 33 THAN victims and 13 UCED victims. Some of the clinical findings were not able to be measured in the THAN patients due to lack of equipment or lack of reported information in these 33 cases, so the numbers shown represent the number of positive clinical findings/out of the number cases in which the symptom could be observed or was documented. The results were as follows: Respiratory distress occurred in 22/23 of THAN patients and only in 0/13 of UCED patients. Abnormal chest radiographs were found in 23/25 THAN victims, and 0/9 in UCED patients. The gestational age was less than 36 weeks in 25/31 THAN patients, but only 1/13 UCED patients. The birthweight was less than 2.5 kg in 27/31 THAN patients and in 2/12 UCED patients. A coma that lasted 48 hours or longer occurred in 12/17 THAN patients but only occurred in 1/12 UCED patients. Free ammonia (NH4+) levels greater than 1500 μM occurred in 17/29 THAN patients but only 1/13 UCED patients.
Transient hyperammonemia of the newborn
Permanent neonatal diabetes
Neonatal hepatitis
Hemolytic disease of the newborn
Hemolytic disease of the newborn 
Transient neonatal diabetes
Neonatal diabetes
Neonatal hypoglycemia