Pediatric multiple renal tubular dysfunction syndrome

Introduction to multiple renal tubular dysfunction syndrome in children Multiple renal tubular dysfunction syndrome, Fanconi II syndrome, also known as deToni-Debre-Fanconi syndrome, renal diabetic pygmy with hypophosphatemic rickets, osteomalacia-renal glucosuria-amino aciduria-hyperphosphate syndrome nephrotic osteomalacia glycine phosphate urinary diabetes syndrome, bone-nephropathy syndrome, familial juvenile nephrotic syndrome, Lignac syndrome, Lignac-Fanconi syndrome, Fanconi-Toni-Deber syndrome. basic knowledge The proportion of illness: 0.001% Susceptible people: children Mode of infection: non-infectious Complications: pediatric malnutrition, rickets, proteinuria, hyponatremia, hypokalemia, anemia

The cause of multiple renal tubular dysfunction syndrome in children

(1) Causes of the disease

The etiology of this disease is unknown, most of them are autosomal recessive, individual dominant inheritance, and the metabolic disorder of Fanconi syndrome is shown in Figure 1. This article mainly describes the primary Fanconi syndrome.

The classification of Fanconi syndrome is currently divided into three categories.

1. Primary:

(1) Familial hereditary (AD, ART XLR).

(2) sporadic.

2. Secondary: Secondary Fanconi syndrome is most common in children, seen in glycogen accumulation disease, galactosemia, hepatolenticular degeneration, renal tubular acidosis and lead poisoning, etc., in general, extensively involving the proximal end The disease of renal tubular reabsorption can be caused. In addition to symptomatic treatment, the primary disease should be treated.

(1) secondary to congenital metabolic disorders: cystine disease (AR), glycogenosis (AR), Lowe syndrome (XLR), galactosemia (AR), hereditary fructose intolerance (AR) , tyrosinemia (AR), hepatic-sinusoid degeneration (Wilion disease) (AR).

(2) Acquired diseases: multiple myeloma, nephrotic syndrome, kidney transplantation.

(3) Poisoning: heavy metals (mercury, uranium, lead, cadmium), maleic acid, come to Suer, expired tetracycline, methyl 3-chromone.

3. Proximal tubular syndrome: There is no clinical symptom of proximal tubular syndrome, only mild proximal renal tubular dysfunction.

(two) pathogenesis

The mechanism of the proximal renal tubular dysfunction may be related to the abnormal transport system of epithelial cells, abnormal energy metabolism or concentration gradient defects.

Some people think that the main pathology is that the proximal tubules become shorter, and the glomerular connection is narrowed, resulting in metabolic disorders, hypophosphatemia and varying degrees of acidosis. Also seen in urinary concentrating dysfunction and hypokalemia, but some Renal pathology is normal.

Prevention of multiple renal tubular dysfunction syndrome in children

Most of the symptoms are autosomal recessive inheritance, individual dominant inheritance, the cause is still unknown, preventive measures and genetic disease prevention methods, because there are many people in the family, the genetic disease consultation should be strengthened.

Complications of multiple renal tubular dysfunction syndrome in children Complications, pediatric malnutrition, pruritus, proteinuria, hyponatremia, hypokalemia, anemia

Malnutrition often occurs, growth is slow, complicated refractory rickets, various skeletal malformations, acidosis, proteinuria, hyponatremia, hypokalemia, anemia and multiple malformations.

Symptoms of multiple renal tubular dysfunction syndrome in children Common symptoms Slow growth Hypokalemia constipation Poor appetite Hypophosphatemia Hyponatremia Hypokalemia Whole blood cell reduction Photophobic proteinuria

1. General performance:

In a family, many people develop symptoms. The baby begins to develop 4 to 6 weeks after birth. It is characterized by slow growth, weakness, poor appetite, vomiting and polyuria. Constipation is also common. Most patients suffer from malnutrition, fever, vomiting, dehydration and acidity. Poisoned and hospitalized, can also be expressed as polydipsia and polydipsia, polyuria.

2. Refractory rickets:

Although older children are treated with vitamin D, they are still active rickets, showing short stature and skeletal deformities.

3. Mixed renal tubular acidosis performance.

4. Low molecular tubular proteinuria.

5. Normal blood calcium, hypophosphatemia, increased alkaline phosphatase, hyponatremia, hypokalemia.

6. Anemia and multiple malformations:

Congenital aplastic anemia, in addition to the reduction of whole blood cells, there are signs of multiple congenital malformations, the most common skin brown pigmentation, especially around the face, nasolabial fold, followed by skeletal deformities, such as thumb deficiency Such as or deformity, microcephaly, etc., may also have kidneys, heart and other deformities.

7. Metabolic abnormalities:

Normal blood sugar, urine sugar positive, blood carbon dioxide binding capacity and urine pH is neutral or alkaline, blood amino acid normal or increased, urine amino acid increased.

8. Other:

Most of the primary cases are accompanied by a large amount of cystine in the body, called Lignac-Fanconi syndrome. In addition to the above symptoms, cystine is accumulated in the binding membrane, cornea, etc. Photophobia, and often have a preference for protein foods such as meat.

Examination of multiple renal tubular dysfunction syndrome in children

Serum carbon dioxide binding is low, can be below 10mmol / L (10mEq / L), blood phosphorus is low, blood calcium is normal, alkaline phosphatase is increased, but when renal failure, blood phosphorus and non-protein nitrogen increase simultaneously, blood Calcium is lowered, blood potassium is sometimes low, and high-chlorine acidosis can often occur. Urine sugar is reduced from trace to 5mg/dl, but blood sugar is not high, urine amino acid content is significantly increased, but blood amino acid is not high, and urine excreted amino acids up to a dozen. The type of amino acid discharged by each patient is the same before and after, but the type of each patient is often different. Although the patient has acidosis, the urine pH is often relatively high, and the urine ammonia content and titratable acidity are low. Conventional X-ray Examination, B-ultrasound, color multi-spectral, electrocardiogram, etc., can be found abnormalities such as congenital heart disease, skeletal deformities, and kidney deformities.

Diagnosis and diagnosis of multiple renal tubular dysfunction syndrome in children

According to the characteristics of clinical manifestations, family history, X-ray examination, skeletal malformation and developmental disorders can be diagnosed, from the increase of urinary alkali and amino acids and serum alkaline phosphatase, can not be compared with other types The difference between rickets is mainly due to the increase of urine sugar, which is accompanied by short stature and sputum (anti-vitamin D), indicating that renal tubular dysfunction is multifaceted, if there is hyperchloreosis and hypokalemia, It can be diagnosed. For patients with obvious hypokalemia, potassium should be added first in the glucose tolerance test. Because potassium enters the cell when glycogen is deposited, the blood potassium is seriously reduced, and a shock-like reaction often occurs.

Different from other types of rickets, the urinary alkali and amino acids increase and serum alkaline phosphatase increase, urine sugar increase and urine protein positive, growth retardation and anti-vitamin D rickets performance, as well as high chlorine Acidosis and hypokalemia can help identify, indicating that renal tubular dysfunction is multifaceted.

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