What is Alport syndrome?

This is the 2731st article of Da Yi Xiao Hu

Unfortunate family

There is a family suffering from kidney disease in Neihuang County, Anyang City, Henan Province. Twelve family members in four consecutive generations have suffered from kidney disease, 10 of whom died from the disease. All of them were under 40 years old, and the disease deteriorated rapidly and was difficult to treat.

The 12th person who was infected with the disease was the first college student in the family's four generations. In order to save this young life, the family, who had been reluctant to disclose the history of kidney disease, decided to seek help from the outside world. After a series of diagnoses and genetic confirmation by doctors, the disease in the family was confirmed to be Alport syndrome.

What is Alport Syndrome?

Alport syndrome, also known as eye-ear-kidney syndrome, is one of the most common hereditary nephritis. The main mode of inheritance of the disease is X-linked dominant inheritance, and the pathogenic gene is located in the middle of the long arm of the X chromosome. Therefore, the inheritance of the disease is related to gender. The disease is passed from father to daughter but not from son to son, and from mother to son and daughter to daughter. Most of the cases occur before the age of 10, with hematuria (deformed red blood cell hematuria) as the first and prominent manifestation, intermittent or persistent macroscopic or microscopic hematuria, which is often aggravated by upper respiratory tract infection, pregnancy or fatigue. Renal function can be chronically progressive, especially in men, and end-stage renal failure often occurs at the age of 20-30. It is often accompanied by high-frequency sensorineural deafness. 10%-20% of patients have eye lesions, including strabismus, myopia, nystagmus, corneal pigmentation, keratoconus, spherical lens, cataracts and fundus lesions.

What are the symptoms of Alport syndrome?

1. The most common renal manifestation is hematuria, which is mostly glomerular hematuria.

2. Hearing impairment: Hearing impairment is manifested as sensorineural hearing loss, which occurs in the cochlea. The hearing loss is progressive and not completely symmetrical on both sides. Initially, the hearing loss is in the high-frequency area and needs to be diagnosed with an audiometer. Gradually, it affects the entire sound range and even affects daily communication and conversation.

3. Eye lesions: Eye lesions include anterior lenticule, punctate retinal lesions around the macula, retinal equatorial retinal lesions, and macular retinal lesions.

4. Blood system abnormalities: AMME syndrome is Alport syndrome accompanied by blood system abnormalities, mainly manifested as Alport, mental retardation, midface dysplasia and elliptocytosis.

5. Diffuse leiomyoma: Some families or patients with juvenile Alport syndrome have significant smooth muscle hypertrophy. The trachea, esophagus and female reproductive tract (such as clitoris, labia majora and uterus) are commonly affected, and corresponding symptoms appear, such as difficulty breathing and swallowing.

6. Other authors have reported certain lesions, such as thyroid disease, posterior pontine neuritis, IgA deficiency, mental illness, ascending aortic aneurysm, fibromuscular dysplasia, anorectal malformation, neurofibromatosis type I and Turner-like syndrome.

How to prevent and treat Alport syndrome

There is no specific treatment for this disease. Avoid infection, pregnancy, fatigue and drugs that damage the kidneys. Once renal insufficiency occurs, the intake of protein and phosphorus should be limited, and high blood pressure should be actively controlled to prevent acquired factors from accelerating the progression of the disease.

For patients with Alport syndrome who develop end-stage renal disease, the most effective treatment is kidney transplantation.

Although the pathogenic gene of Alport syndrome has been identified, which has laid a certain foundation for gene therapy, further efforts are needed to implement related gene therapy.

Author: Baoshan Branch of Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine

Dr. Xia Lemin, MD, Department of Hematology