Pediatric nail-patella syndrome
Introduction
Introduction to Pediatric Nail-Sacral Syndrome Nail-patella syndrome (nail-patellasyndrome) is a well-known hereditary nail and tibia dysplasia characterized by a variety of bone abnormalities, initially affecting the elbow and knee, and associated kidney disease, with a few cases of eye and vascular abnormalities. It is characterized by GBM characteristic ultrastructural anomalies. basic knowledge Sickness ratio: 0.0001% Susceptible people: children Mode of infection: non-infectious Complications: Hypertension Renal failure Osteoarthritis Bladder ureteral reflux Kidney stones
Cause
Pediatric nail - the cause of tibial syndrome
(1) Causes of the disease
Nail-sacral syndrome is an autosomal dominant genetic property that is linked to the ABO blood group and the adenylate kinase. The gene locus is on the 9th pair of chromosomes and has a high penetrance. Looij Based on his own data and data, if a patient with this syndrome family has obvious clinical kidney performance, the risk of developing kidney disease is 1/4, and the probability of developing renal failure is 1/10. .
(two) pathogenesis
This disease is characterized by multiple skeletal abnormalities; more than half of them have renal lesions. It is speculated that ultrastructural damage and GBM abnormalities in this patient are common disorders of collagen synthesis in the basement membrane. In some cases, hydroxyproline glycosides and mucopolysaccharides Excretion in the urine is increased. There is no special discovery in the early stage of the disease. Non-specific changes can be seen later, including local basement membrane thickening, tubule atrophy, interstitial fibrosis, and different degrees of glomerular sclerosis. Vascular clearing and sclerosis are associated with hypertension, specificity seen by electron microscopy, glomerular basement membrane has many irregular translucent areas, adult scorpion shape, staining with phosphotungstic acid can show collagen in glomerular basement membrane The fibrils are characteristic changes in the pathology of this disease. Immunofluorescence is usually negative, but in the hardened part, IgM and C3 are deposited along the inner layer of the glomerular capillary wall.
Prevention
Pediatric nail-sacral syndrome prevention
Nail-sacral syndrome is an autosomal dominant genetic property with a high penetrance. General prevention methods can refer to genetic disease prevention measures. To reduce the incidence of birth defects, prevention should be carried out from pre-pregnancy to prenatal: premarital Physical examination plays an active role in preventing birth defects. The size of the examination depends on the examination items and contents, including serological examination (such as hepatitis B virus, treponema pallidum, HIV), reproductive system examination (such as screening for cervical inflammation), common Physical examination (such as blood pressure, electrocardiogram) and asking about family history of the disease.
Personal past medical history, etc., do a good job in genetic disease counseling, pregnant women to avoid harmful factors, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals, etc., prenatal care during pregnancy The system needs to screen the birth defects of the system, including regular ultrasound examination, serological screening, etc., and if necessary, chromosome examination. The nail-sacral syndrome is an autosomal dominant genetic property, and the ABO blood group and The adenylate kinase is linked, and the gene locus is on the 9th pair of chromosomes. Once an abnormal result occurs, it is necessary to determine whether to terminate the pregnancy; the safety of the fetus in the uterus; whether there is a sequelae after birth, whether it can be treated, How to prognose, etc., take practical measures for diagnosis and treatment.
Complication
Pediatric nail-sacral syndrome complications Complications Hypertension Renal failure Osteoarthritis Bladder ureteral reflux Kidney stones
Can be complicated by hypertension, renal failure; can occur nutritional disorders, osteoarthritis; can also be complicated by vesicoureteral reflux, kidney stones and so on.
Symptom
Pediatric nails - symptoms of sacral syndrome Common symptoms Nail dystrophic toe nails in the long pointed head and knuckle deformity humeral loss or dystrophic dystrophic nails - bone quadruple syndrome renal pelvis obtuse angle arc shadow hematuria
1. Clinical manifestations of kidney involvement More than half of patients with nail-sacral syndrome have no obvious clinical manifestations of the kidney. In patients with clinical renal manifestations, the characteristic manifestations are benign nephropathy. The most common symptoms include different degrees of proteinuria, microscopic hematuria. , edema and hypertension, a study found that 56% of patients with abnormal urine in the urine, urinary enrichment ability, uric acid or protein secretion abnormalities, about 10% of patients progress to end-stage renal failure, collection system repeat Malformations are more common, and there are few papers published on the long-term prognosis of this syndrome. There are reports that 10% of patients develop end-stage renal disease, and Meyrier et al reported two families, showing the diversity of renal lesion progression. A family, a 64-year-old male patient with proteinuria for 20 years, had only mild insufficiency in kidney function, while his brother died of renal failure at the age of 25.
In another family, twins, one gradually progresses to end-stage renal failure, while the other long-term only proteinuria, the literature shows that the degree of ultrastructural damage seems to be related to the severity of the clinical manifestations and the course of the disease. Small, in the literature report, the number of kidney stones in this syndrome is not equal to the number of congenital urinary tract malformations. In addition to glomerular basement membrane defects, it has been reported that radiological examination revealed that the kidney and urinary tract of this syndrome have other Structural abnormalities, including: pyelectasis and cortical scars, suggesting vesicoureteral reflux; unilateral nephrotic condensation with double ureter and double renal pelvis; unilateral renal dysplasia and contralateral kidney; pyelectasis and kidney stones,
2. Extrarenal performance
(1) skeletal and nail damage: the most prominent finger (toe) nail atrophy or dysplasia or even absent, the syndrome refers to (toe) nail abnormalities including discoloration, spoon-shaped armor, longitudinal sputum, finger (toe A deficiency or nutritional disorder, triangular armor shadow, these performances are often symmetrical, nails are more susceptible to toenail, the frequency of thumb involvement is the highest, about 90% of patients, 80% have unilateral or bilateral sacral dysplasia or Completely absent, these changes may be related to the lateral reduction of joint flexion, which can lead to knee valgus deformity, abnormal tibia can also lead to osteoarthritis, osteoarthrosis and joint effusion, other skeletal deformities include scoliosis, elbow deformity , thickening of the scapula, incomplete dislocation of the humeral head, conical humeral angle, etc., 80% of patients with this syndrome have open sacral tendon, protruding forward and upward, known as the humeral angle, elbow abnormalities including dysplasia, The posterior process of the distal radius of the humerus causes an increase in the angle of the lifting and extension, and the function of the supination is limited. The dysplasia of the humeral head and the abnormality of the ankle joint can be seen in the report.
(2) eye abnormalities: In addition, often accompanied by eye abnormalities, such as iris heterochromia, congenital glaucoma, cataract, etc., in the above performance, the nail is missing or hypoplasia, unilateral or bilateral humerus is missing or Dysplasia, posterior tibial bone spur, elbow and humeral deformity, etc., is called nail-bone quadruple sign.
Examine
Pediatric nail-sacral syndrome examination
Urine test has different degrees of proteinuria, microscopic hematuria, abnormal sediment; decreased urine concentration, urinary pH ; advanced muscle liver, increased NPN; renal biopsy showed glomerular basement membrane worm-like lesions and basement membrane There is a dense bundle of cross-collision fibers inside, which is characteristic of this disease. X-ray examination revealed various abnormalities, such as nail-bone quadruple syndrome; radiological examination also found other abnormalities of the kidney, urinary tract, such as kidney atrophy, kidney expansion and so on.
Diagnosis
Diagnosis and differential diagnosis of pediatric nail-sacral syndrome
The main diagnosis of this disease is family history, typical clinical manifestations, X-ray signs of bone and proteinuria; electron microscopy of renal biopsy has diagnostic value.
The diagnosis of this disease is not difficult, most of them are caused by difficulty in walking due to lack of humerus. According to typical skeletal changes, it can be diagnosed, and kidney damage can be diagnosed. Radiological examination shows sacral angle, which has characteristic diagnostic significance. The patient has ultrastructural changes in the glomerular basement membrane without bones, skin, nails, and other typical manifestations of the syndrome. These patients are considered to be the type of frustration or single nephropathy of the syndrome, but these The electron micrographs published by the Institute do not strongly support this view. It is not possible to judge kidney biopsy specimens only by glomerular basement membrane moths. The fibrils must be identified by phosphotungstic acid staining.
