We report the case of a 50-year-old man who was evaluated in the Urology Department of our hospital for recurrent lithiasic renal disease since 36 years of age.
In total, he had formed 12 spontaneous calculi of the last calculus a few weeks before going to our unit.
Personal history ruled that since the first years of life he had a deformity of the lower limbs (LLCS), with a special right arcuate outward and left inward, which made him walk
As it did not improve, at 13 years of age, she underwent surgery for both lower extremities, subsequently improving apparent walking.
In 1996 he presented a multiple fracture in the left lower limb in relation to a coche accident, requiring several surgical interventions.
Currently, the patient is waiting for the placement of a prosthesis in the knee.
She has been treated with oral calcium for many years.
In the last months he has been detected an arterial hypertension that was first treated with enalapril and later with amyloidosis.
Family history: The patient has two brothers and three children (two men and one woman), and all are healthy without bone alterations.
His parents have already died, but he knows that his father had a recurrent lithiasic kidney disease, so he was operated on several occasions.
Clinical presentation: Weight: 67.2 kg. Talla: 148 cm. Low stature.
Genu varo bilateral.
The rest, without pathological findings.
Baseline biochemical blood tests performed on the patient are shown in Table 1.
In addition, he had an uremia of 55 mg/dl (reference value [VR]: 10-50), an ionized calcium of 1.28 mmol/l (VR: 1.12-1.35) and a magnesemia of 1.8 mg/dl.
In the metabolic and renal function study performed in 24-hour urine, the rate of tubular proteinuria was 5.544 ± 3.340 (GFR), slightly decreased by 74.43 ml/1.73 mTP2, and tubular reabsorption by 0.91 ± 0.395 mg, respectively (GFR/0.350, 74.43 mg/1.73VR;
β2-microglobulin and α1-microglobulin in urine were normal, ruling out tubular proteinuria.
Serum electrolytes, serum acid and oxalate were normal in both blood and urine.
Glycosuria was never detected.
The study of amino acids in blood and urine, clearance and tubular reabsorption of each of them were normal.
Bicarbonatemia in capillary blood was normal.
Urinary pH was repeatedly alkaline, and citraturia was in the lower limit of normal, being 399 mg/24 hours (VR: > 320 mg/24 hours).
1.
In order to rule out incomplete renal tubular acidosis, an acidification test was performed after an oral ammonium chloride overload according to the previously described protocol11.
At the time of maximum acidity, urinary pH was above 5.5 (VR: 4.89 ± 0.24) and the maximum titratable acidity levels of tubular acidosis (q12.17q54, renal elimination: 1973 ± 107 μ).
An oral calcium overload was performed after 7 days of a calcium and salt diet, according to the protocol described above.
Prior to normal calcium overload 0.2mg fasting and after high vitamin D diet remained unchanged renal absorption increased calcium/creatinine ratio in urine isolated from voiding was 0.17 mg/mg.
The radiological study repeatedly performed (simple abdominal radiography and intravenous urography) showed a very important bilateral medullary nephrocalcinosis.
Genetic study: In the molecular study performed on the patient (polymerase chain reaction and bidirectional sequencing), a change in homozygosis (G.48A.48+4[NM S>c]) was found in homozygosis>08+5>34.
The in silico analysis did not solve the benignity or pathogenicity of the variant, so we proceeded to study the segregation of the variant in its three children, showing that the three had the same change in SLC34.
The messenger RNA (mRNA) study could not be performed.
The metabolic and renal function study of the three children was normal, except that the two men had only mild hypercalciuria13,14.
