dwarfism
Introduction
Introduction to Dwarfism Anyone who is less than 30% of the standard height of a child of the same race, age, and gender, or an adult height of 120 cm or less, is called a dwarf or short stature. Dwarfism causes physical growth retardation due to insufficient growth hormone secretion due to various reasons. The cause of dwarfism can be attributed to two aspects: congenital factors and acquired factors. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: pituitary tumor pituitary short stature
Cause
Cause of dwarfism
Pituitary factor (20%):
For endocrine gnomes. Due to congenital (primary) or acquired (secondary) reasons, anterior pituitary dysfunction, insufficient growth hormone secretion, hindering body growth and development.
Cretin disease (15%):
Thyroid hormones are closely related to bone maturation. When the thyroid gland is low in childhood, the ossification of the cartilage and the growth of the teeth are hindered, and the time of occurrence of each long bone ossification center is significantly delayed, affecting the development and maturity of the bone path, resulting in short stature.
Cartilage developmental disorders (28%):
The disease is weak due to the growth of cartilage, and the growth of the long bone length is slow, forming a severe short deformity, family hereditary, not endocrine. The clinical manifestations are: 1) the length of the trunk bone is normal, and the limbs are obviously short, the lower body is significantly shorter than the upper body; 2) the lordosis of the spine, the front of the abdomen, the back of the buttocks, the fingers are short and short; 3) the mental development is normal; 4) Sexual organs are normal and have reproductive capacity.
Ovarian hypoplasia (18%):
This disease, also known as Turner syndrome, is a female congenital genetic deficiency. The patient has ovarian hypoplasia with dwarfism. Its characteristics are: 1) the closer to puberty, the slower the growth and development; 2) the genital dysplasia, primary amenorrhea; 3) the body is short and fat, with a shielded chest chest; 4) the patient's urinary gonadotropin is significantly increased, which is Pituitary dwarfism is just the opposite.
Prevention
Dwarf prevention
Intrinsic children should actively prevent heart failure and infection. The prevention of intrinsic is based on the prevention of congenital diseases. Precautions should be taken 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), reproductive system examination (such as screening for cervical inflammation), Ordinary 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 much as possible, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals. Systemic birth defect screening is required during antenatal care during pregnancy, including regular ultrasound, serological screening, and, if necessary, chromosomal 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, and how the prognosis is. Take practical and feasible treatment measures.
The prenatal diagnostic techniques used are: 1 amniocentesis cell culture and related biochemical tests (amniotic puncture time is appropriate for 16 to 20 weeks of pregnancy); 2 maternal 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 malformation; 5 chromatin determination of villus cells (40 to 70 days of conception), predicting fetal sex to help diagnose X-linked genetic diseases; 6 application gene linkage analysis; 7 fetal microscopy.
Through the application of the above technology, the birth of a fetus with severe genetic diseases and congenital malformations is prevented.
Complication
Dwarf complication Complications pituitary pituitary dwarf disease
There may be manifestations of increased intracranial pressure such as visual impairment, headache, vomiting, and neurological symptoms such as weakness, lethargy, and convulsions, and simultaneous diabetes insipidus.
Symptom
Symptoms of dwarfism Common symptoms Abnormal short growth hormone secretion too low growth slow
Diagnostic criteria for pituitary dwarfism: 1 height lower than the same age, same sex normal person - 2S or 3th percentile (according to Stadiometer); 2 growth rate <4cm / year; 3X line bone age behind the same age, the same The normal gender average was over 2 years old (according to the Greulich-pyle map); 4 three growth hormone (GH) challenge tests (referring to levodopa, clonidine and GHRH challenge test); blood GH peaks were <10ng/L; Other factors that cause growth retardation.
Signs: Infants with onset of growth are slower than 1 to 2 years old, growth rate is less than 4cm per year, short stature, height is mostly less than 130cm, and the posture is relatively well-proportioned. The child has a late closure of the cardia, delayed tooth growth, and short bones. The brain develops normally and the intelligence is similar to that of the same age. The hair is less soft, the skin is finer, the subcutaneous fat is rich, the bone age is smaller than the age, the muscle development and physical strength are not like the age children, and the character often remains childish. Adolescence is often delayed, and secondary sexual traits are absent. If there is gonadotropin deficiency at the same time, it remains sexually naive. The male testicle is small or cryptorchidism, the prostate is small, the beard, mane, pubic hair is absent, and the tone is high. Females presented with a naive uterus, primary amenorrhea, undeveloped breasts, arms and vulva, no mane and pubic hair. From the development to adulthood, the skin's elasticity is reduced and wrinkled, but the face is still immature / forming a characteristic "little old child" appearance.
The age of growth retardation of secondary dwarfism is more than 4 years old, and there may be manifestations of increased intracranial pressure such as visual impairment, headache, vomiting, and neurological symptoms such as weakness, lethargy, and convulsions, and simultaneous diabetes insipidus.
Examine
Dwarf examination
1. Growth hormone stimulation test commonly used arginine, insulin, clonidine, L-dopa, exercise, sleep stimulated secretion test. The growth hormone peak is <10 ng/ml.
2. Nighttime 12h growth hormone stimulation test showed a decrease in pulse.
3. Growth hormone releasing hormone test to identify pituitary and hypothalamic lesions.
4. Growth medium measurement is often lower than normal.
5. Blood T3, T4, and TSH were mostly normal or low.
6. Bone age determination is often delayed.
7. Women undergoing chromosome examination to exclude Turner syndrome.
8. Cranial space occupying lesions can be used for cranial radiography and CT imaging.
Diagnosis
Diagnosis of dwarfism
Diagnostic points :
1. The body weight is often normal at birth. After 1 to 3 years old, the difference between children and the same age is more and more obvious. In adulthood, the height is usually below 130cm, but the body proportion, intelligence ratio and mental development are normal.
2, adolescent secondary sexual deficiencies such as, no sputum, pubic hair, male testis, penis and prostate are not developed or poor development, women without menstruation, breast, uterus, ovary and vulva are not developed.
3, X-ray film shows that the bone age is childish, and the bones are not fused for a long time.
4. The level of fasting plasma growth inhibition is lower than normal and is not sensitive to the stimulatory response of insulin or arginine. Most patients may have low levels of gonadotropins and sex hormones.
Differential diagnosis:
Children with short stature should be distinguished from the following:
1. Growth and development disorders caused by chronic diseases such as chronic infection, chronic liver disease, malnutrition, congenital heart disease, congenital tubular disease.
Second, other endocrine and metabolic diseases such as dysplasia, ovarian hypoplasia, cartilage malnutrition, glycogen accumulation and mucopolysaccharidosis.
Third, the family short parents are short or have short stature in the family, but the intelligence is normal and sexual development is normal.
Fourth, puberty delay (physical growth retardation) children with delayed puberty, not only sexual development is late, its physical development including bone development can be 2 to 4 years behind normal children, normal intelligence. Once it reaches puberty, it changes a lot, grows faster, and finally reaches a completely normal height.
Fifth, the cause of primordial dwarfism is still unclear. The growth hormone of the child is normal, and the development from the fetal period is delayed. Therefore, the physique at birth is very small, and the gnome is obvious in infancy. The intelligence is normal. Some cases are accompanied by other malformations, such as abnormal changes in the head, eyes, ears, neck and heart.
