[MIM 222 700]

(hyperdibasic aminoaciduria type II,  dibasic protein intolerance with lysinuria)

Very rare disease except in Italy and Finland (1/60.0000). Autosomal recessive transmission of a mutation of the SLC7A7 gene on 14q11.2. This mutation results in an increase in renal losses and decreased intestinal absorption of so-called 'dibasic' amino acids: lysine, ornithine and arginine.

Clinical presentation:

-        interruption of the urea cycle.

-        digestive problems upon discontinuation of breastfeeding, vomiting and postprandial coma (related to hyperammonemia), diarrhea, hepatosplenomegaly, growth retardation. High levels of lysine in the urine.

-        osteoporosis. 

-        risk of interstitial pneumonia and of pulmonary alveolar proteinosis due to the fact that the protein coded for by SLC7A7 is also the target of the GM-CSF that stimulates the alveolar macrophages involved in the cycle of the surfactant.The mutation decreases their activity.

-        anemia with sometimes an associated immune deficit or episodes of lymphohistiocytic hematophagocytosis. 

-        renal involvement: proximal tubulopathy, hypertension, sometimes renal failure.

Treatment: 

-         low protein diet,

-         citrulline supplements: 50 - 100 mg/kg/day

-         in case of hyperammoniemia despite the low protein diet: Na benzoate or Na phenylbutyrate 50-100 mg/kg/day

-         in case of hypertriglyceridemia: exclude a hemophagocytic syndrome; hypolipidemic diet with  omega 3 fatty acids

-         carnitine supplementation

Anesthetic implications: 

check NH3, hemoglobin, renal function, chest X-Ray + SpO2 at room air. Cautious positioning because of osteoporosis. 

Avoid using a continuous infusion of propofol in case of hypertriglyceridemia.

References : 

-      Paquet C, Karsli C. 
Technique of lung isolation for whole lung lavage in a child with pulmonary alveolar proteinosis. 
Anesthesiology 2009; 110: 190-2.

-         Doireau V, Fenneteau O, Duval M, Perelman S et al. 
Intolérance aux protéines dibasiques avec lysnurie : aspect caractéristique de l’atteinte médullaire. 
Arch Pédiatr 1996 ; 3: 877-90.

-        de Lonlay P, Dubois S, Valayannopoulos V, Depondt E et a. 
Intolérance aux protéines dibasiques avec lysinurie.  Chap 10 in Prise en charge médicale et diététique des maladies héréditaires du métabolisme Springer 2013

Updated: January 2021