Metabolic Disorders of Amino Acids MCQs

Recurrent/ resistant Hypoglycemia This condition should be considered when the infant fails to maintain normal BGL despite a GIR of 12 mg /kg/min or when stabilization is not achieved by 7 days of therapy. High levels of glucose infusion may be needed in these infants to achieve euglycemia. Hyperinsulinism must be excluded because it is the most common cause of persistent hypoglycemia. Hyperinsulinemic hypoglycemia can be congenital [due to mutations affecting the regulation of insulin secretion from the pancreas] or acquired [neonates with maternal diabetes, birth asphyxia, polycythemia, Rh incompatibility, and severe intrauterine growth restriction, Beckwith-Wiedemann syndrome. etc.] Many patients may have underlying metabolic disorders or hypocortisolism Hydrocortisone is often considered in such cases. Reference: AIIMS Protocols In Neonatology, 3 rd Edition, Volume 2, Page 305

Cerebral palsy (CP) is a group of permanent neurological disorders affecting movement, posture, and muscle tone, resulting from brain damage that occurs before, during, or shortly after birth. Risk factors of developing cerebral palsy Prenatal insult Preterm birth Birth asphyxia CNS infections Toxin exposure like bilirubin (Kernicterus) CNS hemorrhage Metabolic disorders KEY TAKEAWAYS: Cerebral palsy is a non-progressive motor disorder that affects a growing brain. Hence, insult after brain growth is nearly complete, does not cause Cerebral palsy. Tags: Topic: CEREBRAL PALSY Difficulty level: GOOD TO KNOW PYQ: NEET PG 2021 Reference: Nelson textbook of pediatrics, 21 st ed., pg. 3168

This child is likely to be dehydrated from losing fluid through vomiting and diarrhoea, and may not have adequate oral intake to replace losses. This has resulted in severe dehydration, evident from the increased HR (due to compensation for a low blood volume in attempt to increase BP), increased cap refill time and low BP (indicating uncompensated shock), and pale and clammy appearance. KEY TAKEAWAYS: Hypovolemic shock occurs due to a significant reduction in intravascular volume, leading to inadequate tissue perfusion and oxygen delivery. This can result in cellular hypoxia, metabolic acidosis, and multi-organ dysfunction if untreated. Tags: Topic: SHOCK Difficulty level: MUST KNOW Reference: Manual of paediatric emergencies & critical care, 2 nd ed., pg. 158

Although the patient's serum glucose is decreasing, her metabolic acidosis has not yet resolved and will require continued intravenous insulin therapy and IV Fluid for treatment. The patient should not be converted to subcutaneous insulin until her glucose has normalized, her bicarbonate level is greater than 18 mEq/L, and her serum pH is greater than 7.3. Because of the risk of causing hypoglycemia with continued insulin therapy, dextrose should be added to her fluids. Bicarbonate therapy has not been shown to be effective in the treatment of metabolic acidosis associated with DKA and can actually be harmful. Reference: AIIMS PICU Protocols 2022, Pages 411-419

Vitamin B6, i.e., Pyridoxine administration is helpful at 200 mg/day in many patients of Classic Homocystinuria. These patients are milder and have a better outcome than the non-responsive forms. However, methionine restriction to keep the plasma homocysteine levels low is the mainstay of therapy. Regarding other options Hydrocortisone is the therapy needed in CAH. Some forms may need additional drugs. Phenylketonuria needs dietary restriction of phenylalanine and a low-protein diet Alkaptonuria responds to Nitisinone to inhibit pigment production. Reference: OP Ghai 10 th Edition, Pages 684-685

Hypoglycemia and Hypocalcemia are the two major metabolic complications seen in infants of diabetic mothers. Hypoglycemia develops in approximately 25-50% of infants of mothers with pregestational diabetes and 15-25% of infants of mothers with gestational diabetes, but only a small percentage of these infants become symptomatic. Apart from hypoglycemia, hypocalcemia is another common metabolic complication seen in these babies and results from the diminished production of parathormone in the 1 st week of postnatal life. Now in this question, since Serum glucose is normal, next logical thing to check is serum calcium. Reference: OP Ghai 10 th Edition, Page 182; Nelson 21 st Edition, Chapter 127

Treatment of Rett Syndrome Trofinetide is a new drug, approved for use in 2023 in children aged 2 years and above with Rett Syndrome. The drug is commercially marketed as Daybue. It is a novel synthetic analogue of the amino terminal tripeptide of IGF-1 The drug acts by decreasing neuroinflammation and supporting synaptic function tripeptide GPE. L-Carnitine & Melatonin may be helpful in a few cases. Reference: NIH Publications 2023

Intrauterine exposure of an unborn child to elevated phenylalanine concentrations due to maternal PKU can disrupt embryo-fetal development. Effects include facial dysmorphism resembling fetal alcohol syndrome, microcephaly, mental impairment, and malformations especially of the heart. Hypopigmentation occurs owing to a lack of pigment formation. Musty or mousy urine odour is also produced. None of the other maternal conditions listed above would lead to the clinical features described in this vignette. Maternal diabetes leads to macrosomia not growth restriction. Reference: Nelson textbook of Pediatrics, 1 st SA ed., pg. 637