[Late onset 3-HMG-CoA lyase deficiency: a rare but treatable disorder]. / Déficit en 3-HMG-CoA lyase à révélation tardive : savoir reconnaître une maladie rare mais traitable.

3-Hydroxy-3-methylglutaric aciduria is a rare autosomal recessive genetic disorder due to a deficiency of the 3-hydroxy-3-methylglutarylCoA lyase (HMG-CoA lyase), a mitochondrial enzyme involved in ketogenesis and in the final step of l-leucine catabolism. HMG-CoA lyase deficiency can lead, in particular circumstances, such as fever, prolonged fasting or digestive disorders, to brutal and severe hypoglycemia with metabolic acidosis and sometimes fatal coma. We report on a new case of 3-hydroxy-3-methylglutaric aciduria particular by its late onset in a 3-year-old patient. Molecular investigation identified two new sequence modifications in the HMGCL gene: c.494G>A (p.Arg165Gln) and c.820G>A (p.Gly274Arg). We remind about this case report that the therapeutical is mainly preventive and allows a very good prognosis for this disease. Long-term treatment consists in limited fasting time, continuous low protein diet and l-carnitine supplementation. Preventive measures are essential: prevention of fasting and emergency treatment during intercurrent infections.

[A cause of intracerebral calcifications that should be known: pseudohypoparathyroidism Ib]. / Une cause de calcifications intracérébrales à connaître: la pseudohypoparathyroïdie de type Ib.

In children, pseudohypoparathyroidism (PHP) is a rare but classical cause of basal ganglia calcifications. It is caused by resistance to parathormone (PTH). Hypocalcemia, which may be symptomatic, is its main feature. We report the case of a 13-year-old boy, affected by type Ib PHP revealed by hypocalcemia and seizures, with basal ganglia calcifications on the CT scan. We describe the characteristics of the 2 main types of PHP and emphasize the search for this disease when basal ganglia calcifications are discovered, even fortuitously, on a cerebral CT scan.

Duplication of the leg--renal agenesis: congenital malformation syndrome.

A case is given of a male born with a duplication of the left leg and ipsilateral kidney agenesis. Although the etiology is unknown, we believe this association represents a congenital malformation syndrome. It is a polytopic developmental field defect. The growth factor IGF-I produced by the intermediary mesoderm or mesonephros (embryonary kidney) could be implicated in the induction limb development and the application of FGF-8 protein to the flank of young chick embryos inducing the development of additional limbs. It is possible that one or more of the growth factors produced by the mesonephros take some cells of the intermediary mesoderm out of their renal way to form a supernumerary limb.