Michelis-Castrillo syndrome or Familial Hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC)
The other day, I had dinner with the chief of Nephrology at Lenox Hill hospital in Manhattan, Dr. Michael Michelis. In the dinner conversation, he was describing his days in Pittsburg where he had once worked under the direction of Dr. Drash. Interestingly, he was asked to see a family of siblings with an interesting tubular disorder. At that time he didn’t know what exactly he was dealing with. He called it “Decreased bicarbonate threshold and renal magnesium wasting in a sibship with distal renal tubular acidosis : Evaluation of the pathophysiologic role of parathyroid hormone” and published it in the literature. Since then, over 50 cases of similarfindings have been described: hypomagnesemia, hypercalciuria, and nephrocalcinosis. He was told by someone else that the disease has been named after him as Michelis-Castrillo syndrome. In a recent paper in JASN, it’s quoted as “Gitelman syndrome, and autosomal recessive familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) are two hereditary hypomagnesemic renal disorders. FHHNC was first described by Michelis et al. in 1972 (Michelis-Castrillo syndrome). " Dr Castrillo also described this entity later in the Spanish literature (Castrillo JM, Rapado A, Traba ML, Esbrit P, Hernando L: Nefrocalcinosis con hipomagnesemia. Nefrología 3:159–165, 1983), almost 11 years after it was initially described by Dr.Michelis. The disease hence gets its name now as Michelis-Castrillo syndrome.
Since then, patients of at least 50 different FHHNC kindreds have been reported. FHHNC is generally complicated by chronic renal failure (CRF) in early childhood or adolescence. Recurrent urinary tract infections (UTI) and polyuria/polydipsia are frequent initial symptoms. In addition to marked hypomagnesemia, all affected individuals exhibit hypercalciuria and nephrocalcinosis. Additional symptoms at manifestation include nephrolithiasis, abdominal pain, convulsions, muscular tetany, failure to thrive, incomplete distal renal tubular acidosis (dRTA), and hypocitraturia. Some authors reported elevated serum parathyroid hormone (PTH) levels early in the course of the disease, independently of GFR.