A newborn girl appeared normal at birth but within 24 hours...

A newborn girl appeared normal at birth, but within 24 hours she developed lethargy, hypothermia, and apnea. The attending physician suspects a metabolic disorder and orders a panel of labs. Which diagnostic would be the best to distinguish between a urea cycle disorder and a disorder in β-oxidation? Blood glucose Urinary acids Serum fatty acids Plasma glutamine A full blood work up was ordered for this female and the data is presented below. The initial blood ammonia level was elevated at 314 ug/dl (normal range = 17–80) and rapidly rose to 600 ug/dl. The urine orotic acid level was markedly elevated at 473 umol/L creatinine (nl = 0–3). The plasma citrulline level was normal at 10 uM/L (nl = 12–55).

Transcript

00:01 The best diagnostic test which is going to be helpful in distinguishing in the distinguishing of two disorders number one is the urea cycle disorder other one is the disorder in beta oxidation so there's a best diagnostic test that is going to distinguish between these two disorders that best diagnostic test is the measurement of serum fatty acids by measuring the serum fatty acids we can easily distinguish between these two disorders now we talk about the ratio for this choice we have two big reasons that are indicating towards a particular disorder according to the information or the symptoms that are given in the question number first reason is the elevated blood ammonia levels that is in the initial the blood ammonia level was elevated at 314 microgram per deciliters this was the initial blood ammonia level after that it rises it got rises up to 600 microgram per deciliter and this is actually a strong indication a strong indication of the urea cycle disorder why i am saying this that this is the order for the urea cycle disorder but this is a strong indication of the urea cycle disorder because in the urea cycle disorder there is actually an accumulation of accumulation of the ammonia in the blood because the urea cycle why did happen is because the urea cycle is unable to convert ammonia into urea for the excretion because in the urea cycle that's why there's a strong indication that this disease or the symptoms according to this is going towards a clear direction of the urea cycle disorder because in the urea cycle disorder there is actually an accumulation and since there is a disorder the urea cycle is not working properly that's why the urea cycle is unable to convert the ammonia into the urea for the excretion.

04:33 Number second point if we talk about the second reason that why these symptoms are indicating toward the urea cycle disorder is the normal plasma citrulline level that is the normal plasma citrulline levels.

05:00 In the question the plasma citrulline level was normal in the initial the plasma was normal and that was only 10 micro molar per liters and the normal range whatever the normal range lies that normal range is always between 12 to 55 micro molar per liter but in the initial which is actually a normal range we can consider this a normal range very easily but citrulline is actually a key amino acid in the urea cycle.

05:38 The point noted that citrulline is the key amino acid in the urea.

06:06 Now the normal citrulline level suggests that the urea cycle may be functioning correctly because there is a normal and as i have already told that this is a normal range...

Question

Please give Ace some feedback