Missing finger (toe) nails

Introduction A nail-patella syndrome or hereditary osteo-onychodysplasia is a hereditary disease characterized by dysplasia or absence of the tibia. , finger (toe) nail dystrophy, elbow dysplasia, sacral horn and kidney failure. The syndrome of bone and nail damage, the nail abnormality includes discoloration, spoon-shaped nails, longitudinal tendons, finger nails or nutritional disorders, triangular nail shadows. Defects or hypoplasia of the nail, unilateral or bilateral humeral loss or dysplasia, posterior tibial bone spur, elbow and valgus valgus deformity, etc., are called nail-bone quadruple syndrome.

Cause

(1) Causes of the disease

The syndrome is autosomal dominant, and the locus is linked to the adenylate cyclase and ABO blood group on chromosome 9.

(two) pathogenesis

At present, little is known about the pathogenesis of this syndrome. Some people think that it is a collagen disease, and there are abnormalities in the process of collagen synthesis, assembly or degradation. The cytological mechanisms of this disease have not been studied.

The lack of non-glomerular basement membrane damage in pathological changes suggests that the various damages in this syndrome may be due to different mechanisms, and not all lesions are associated with basement membrane abnormalities. A small number of patients developed anti-glomerular basement membrane nephritis, supporting the hypothesis that glomerular basement membrane components are abnormal. Using a monoclonal antibody against the Goodpasture epitope, it was found that the glomerular basement membrane of 2/3 patients with renal biopsy specimens did not bind to the monoclonal antibody, suggesting a basement membrane for this syndrome. There is some degree of heterogeneity in the components, which also suggests the presence of Goodpsture antigen deletion or alteration. It is worth noting that it is not clear whether this is a primary or secondary change in this syndrome.

an examination

Related inspection

Urine routine renal dynamic imaging retrograde pyelography kidney MRI examination kidney CT examination

1. Kidney performance

More than half of the nail-sacral syndrome patients had no significant clinical manifestations of the kidney. In patients with clinical renal manifestations, the characteristic manifestations are benign nephropathy. The most common symptoms are different degrees of proteinuria, microscopic hematuria and tubular urine, edema and hypertension. In one study, 56% of patients had abnormal deposits in the urine, impaired urinary concentration, abnormal uric acid or protein secretion. 30% of kidneys will develop slowly to kidney failure and die of uremia.

Meyrier et al. reported two families showing the diversity of progression of renal lesions. In one family, a 64-year-old male patient has a proteinuria that lasts for 20 years, with only mild insufficiency in his kidney function, and his brother died of kidney failure at the age of 25. One of the twin brothers of another family gradually developed into end-stage renal failure, while the other long-term only proteinuria. The literature shows that the degree of ultrastructural damage appears to have little to do with the severity and duration of clinical manifestations; the number of kidney stones is not equal to the number of congenital urinary tract malformations.

2. Skeletal and nail damage

The syndrome refers to abnormalities of the nails including discoloration, spoon-shaped nails, longitudinal tendons, finger nails or dystrophies, and triangular nail shadows. These manifestations are often symmetrical and exist in 80% to 90% of patients. Nail is more susceptible to nails and has the highest frequency of thumb involvement. About 60% of patients have humeral loss or dysplasia. These changes may be related to a reduction in the lateral side of the joint during flexion, which can lead to knee valgus deformity. Abnormal tibia can also lead to osteoarthritis, osteoarthrosis and joint effusion. 80% of patients with this syndrome have an open humerus, which protrudes forward and upward, called the humeral horn. Abnormal elbows include dysplasia and posterior processes of the distal radius, resulting in increased traction and extension, and limited supination. Individuals were associated with humeral head dysplasia and ankle joint abnormalities.

3. Other

In addition to glomerular basement membrane defects, radiological examination revealed other structural abnormalities in the kidney and urinary tract of the syndrome, including: pyelectasis and cortical scars, suggesting vesicoureteral reflux; unilateral nephrotic condensation and double ureter and double Renal pelvis; unilateral renal dysplasia and contralateral kidney; pyelone dull and kidney stones.

The main diagnosis of this disease is family history. The typical clinical manifestations are X-ray signs of bone and proteinuria. Renal biopsy is performed as necessary.

Clinically more common in adolescents, the main manifestations of kidney damage are proteinuria, microscopic hematuria, edema and hypertension, occasionally nephrotic syndrome, the course of disease is relatively benign, only 10% of patients enter the kidney failure late. Extrarenal manifestations include nail dystrophies, absent bones on one or both sides, elbow deformities, angular pelvis, and other skeletal abnormalities. Most of the disease is caused by difficulty in walking due to lack of humerus. It can be diagnosed according to typical bone changes, and kidney damage can be diagnosed. Radiological examination showed that the humeral angle was a characteristic change and had a clear diagnostic significance.

It has been reported that a small number of patients have ultrastructural changes in the glomerular basement membrane without bones, skin, nails, and other typical manifestations of this syndrome. These patients are considered to be the frustration or single nephrotic variant of the syndrome. . However, the electron micrographs published by these institutes do not strongly support this view.

Judging the renal biopsy specimens can not only use the glomerular basement membrane moth, and the fibrils must be identified by phosphotungstic acid staining. Because of its higher sensitivity, it is more valuable for diagnosis.

Common vesicoureteral reflux; renal pelvis becomes dull and kidney stones, posterior tibial bone spurs, elbow and humeral deformity, etc., even with iris pigment abnormalities.

Differential diagnosis

Finger nail transection is mostly due to personal physiological pressure or local injury caused by nail growth stop. If the supply of blood and circulation is insufficient, the nails will become particularly fragile and fragile; if the center of the nail is gradually sagged, like a spoon, it may mean that the body has cardiovascular or anemia. The soft atrophy of the nail is a clinical manifestation of pseudohypoparathyroidism. Patients with pseudohypoparathyroidism often find rough skin, hyperpigmentation, hair loss, fingernails, soft and atrophy, and even shedding; cataracts can occur in the intraocular lens.

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