Mnemonic: CATCH-22 is used to describe DiGeorge syndrome, with the 22 to remind one that the chromosomal abnormality is found on the 22 chromosomes: Cardiac Abnormality (especially Tetralogy of Fallot) Abnormal facies Thymic aplasia= explains the recurrent infections Cleft palate Hypocalcemia/Hypoparathyroidism: explains recurrent seizures and tetany Gitelman syndrome occurs in older children and features episodes of muscle weakness and tetany associated with severe hypokalemia, and hypomagnesemia. These children have hypocalciuria. Bater syndrome is thought to result from mutations in two genes (NKCC2, ROMK) affecting nephron Na+-K+or K+transpo. These patients typically have a history of polyhydramnios and following bih have recurrent life-threatening episodes of fever and dehydration with the aforementioned electrolyte and acid-base disturbances, hypercalciuria, and early-onset nephrocalcinosis.