Pediatric retinitis pigmentosa-obesity-polydactyly syndrome
Introduction
Brief introduction of children with retinitis pigmentosa-obesity-multiple finger syndrome Laurence-Moon-Biedlsyndrome, also known as Bardet-Biedl syndrome, Biemond syndrome, sexual naive, retinitis pigmentosa, polypoid syndrome, etc. Gonadal dysplasia, retinitis pigmentosa, mental retardation, multi-finger (toe) malformation and other abnormalities are a congenital hereditary disease. basic knowledge The proportion of illness: 0.004%-0.007% Susceptible people: children Mode of infection: non-infectious Complications: epilepsy congenital heart disease deafness
Cause
Pediatric retinitis pigmentosa - obesity - the cause of multi-fingery syndrome
(1) Causes of the disease
The etiology and pathogenesis of this disease are not clear. Patients often have a family history and a history of close relatives. The chromosome examination is often normal. Individually reported male chromosomes are XXY type.
(two) pathogenesis
According to the family survey and analysis, it is consistent with the transmission law of autosomal recessive genetic disease. The three cases reported by Wang Zhendong, the probability of being revealed in the siblings of the family is 75%. Although it is inconsistent with the autosomal recessive inheritance, it may be in the proportion of small families. Due to the high degree, although Bowen has reported a chromosomal abnormality, the sex chromosome abnormality is not the cause, the meaning is not clear, the boundary of the disease is not clear, the main symptoms are often enlarged or absent, and the symptoms of different members of the same family may be completely Or incomplete type, this intricate clinical change, most scholars believe that due to the genetic heterogeneity of this syndrome, it is difficult to imagine a simple genetic defect can cause these different clinical manifestations, different nature of hypogonadism.
Some people have performed autopsy and found that the hypothalamus or pituitary has organic lesions. It is speculated that the cause of this disease may be hypothalamic-pituitary congenital dysfunction, causing insufficient secretion of gonadotropin and other congenital abnormalities.
Prevention
Retinitis pigmentosa in children - obesity - prevention of multi-fingery syndrome
The cause is still unclear. With reference to the prevention of congenital diseases, preventive measures should be carried out from pre-pregnancy to prenatal:
Pre-marital medical examination plays an active role in preventing birth defects. The size of the effect depends on the examination items and contents, including serological examination (such as hepatitis B virus, treponema pallidum, HIV) and reproductive system examination (such as screening for cervical inflammation). General medical examinations (such as blood pressure, electrocardiogram) and asking about the family history of the disease, personal medical history, etc., do a good job in genetic disease counseling.
Pregnant women should avoid harmful factors as far as possible, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals, etc. In the process of antenatal care during pregnancy, systematic screening of birth defects is required, including Regular ultrasound examination, serological screening, etc., if necessary, a chromosome examination.
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 sequelae after birth, whether it can be treated, how to prognose, etc., and take practical measures for diagnosis and treatment.
The prenatal diagnostic techniques used are:
1 amniocytes culture and related biochemical examination (amniotic puncturing time is 16 to 20 weeks of pregnancy is appropriate);
2 pregnant women blood and amniotic fluid alpha fetoprotein determination;
3 ultrasound imaging (applicable in about 4 months of pregnancy);
4X line examination (after 5 months of pregnancy) is beneficial for the diagnosis of fetal skeletal deformities;
5 Determination of sex chromatin in villus cells (40 to 70 days of conception), predicting fetal gender to help diagnose X-linked genetic diseases;
6 application gene linkage analysis;
7 fetal mirror examination.
Through the application of the above technology, the birth of a fetus with severe genetic diseases and congenital malformations is prevented.
Complication
Pediatric retinitis pigmentosa - obesity - complications of multi-fingery syndrome Complications epilepsy congenital heart disease deafness
Male patients have low sexual function, female patients with gonadotropin hypofunction, can be dwarf state, with epilepsy, extrapyramidal lesions, congenital heart disease, deafness and so on.
Symptom
Pediatric retinitis pigmentosa-obesity-multi-finger syndrome symptoms common symptoms growth slow glandular dysplasia osteoporosis thumb three-section ptosis hair sparse eyelids drooping eyeball tremor vulva is naive-type pubic night blind
More common in men, childhood onset, usually between 10 and 15 years old.
Clinical manifestation
(1) Retinitis pigmentosa: often have visual acuity, "night blindness", and some even completely blind, caused by retinitis pigmentosa, ocular tremor, small eyeball, ptosis, internal suede, keratoconus , iris defect, cataract, strabismus, myopia or hyperopia, infantile glaucoma and other eye symptoms.
(2) gonadal insufficiency: the vulva is naive, male infants often have small penis, small testicles or cryptorchidism, and no secondary sexual characteristics during puberty, foreign reports that 75% of male patients have sexual dysfunction 50% of female patients have primary or secondary gonad dysfunction.
(3) Multi-finger (toe) malformation: Most of them have multiple fingers (toes) or fingers (toes), and a few may have other finger (toe) deformities such as finger ends.
(4) Obesity: mainly on the trunk.
(5) Mental retardation: mental retardation of varying degrees.
(6) Slow growth and development: it can be in a dwarf state.
(7) Other abnormalities: deformation of the skull, osteoporosis, drooping eyelids, skin pigmentation spots, etc.
(8) Family genetic history.
2. Clinical classification The Klein and Ammann classifications propose the following clinical classifications:
(1) Complete type: There are 5 manifestations of obesity, mental retardation, vision loss, multi-finger (toe) malformation and gonadal dysplasia.
(2) Incomplete type: no multi-finger (toe) malformation or gonadal dysplasia.
(3) Frustration: There are only one, two or a few obvious changes.
(4) atypical type: no retinitis pigmentosa, may have other symptoms of the eye, such as optic atrophy, external eye muscle paralysis, high myopia, small eyeball, cataract, iris defect or no iris, eyeball deformity.
(5) Extensive type: In addition to the above-mentioned complete type of performance, it is accompanied by other congenital abnormalities or hereditary diseases, such as short stature (dwarf), hair sparse or absent, combined with epilepsy, extrapyramidal lesions, congenital heart disease , deafness, etc.
3. Edwards classification The classification and naming of this disease has always been inconsistent. Edwards divides it into two types according to the increase or decrease of gonadotropin:
(1) Type I: combined with laboratory examination and auxiliary examination results to confirm the diagnosis, Alström syndrome and Edwards syndrome with elevated gonadotropin, called type I (primary gonadal insufficiency).
(2) Type II: Laurence-Moon-Biedl syndrome, which is hypothalamic-pituitary dysfunction and reduced gonadotropin, is called type II (secondary gonadal dysfunction). This classification starts from abnormal physiological and biochemical changes. Promote the study of the etiology and pathogenesis of this syndrome.
Examine
Pediatric retinitis pigmentosa - obesity - multi-finger syndrome examination
Endocrine examination may have hypogonadism and insufficient secretion of gonadotropins.
The laboratory examination of this symptom can be found that the urinary gonadotropin is significantly reduced, the 24-hour urinary gonadotropin (FSH) content is low (usually below the uterine unit of 6 mice), and the male urinary 17-ketosteroid content is lower than normal, urine Neutral hormones were significantly reduced, and thyroid and adrenal function were normal.
1. B-examination see small testicles or cryptorchidism.
2. X-ray examination showed deformation of the skull, normal observation of the saddle, osteoporosis, multi-finger (toe) deformity.
3. EEG examination should be done when necessary, EEG examination may have mild abnormalities, or may have epileptiform discharge.
4. Echocardiography can detect congenital heart disease and so on.
5. Testicular biopsy showed lack of sperm formation in the seminiferous tubule, but no clearing and atrophy of the seminiferous tubule, and no change in interstitial cells.
Diagnosis
Diagnosis and differentiation of children with retinitis pigmentosa-obesity-multi-fingery syndrome
The clinical symptoms of this syndrome are variable, and the complete type is rare. According to the above clinical manifestations and laboratory tests, clinical diagnosis can be made.
Clinical classification and Edwards classification identification are described above.
