The 5th finger is short and curved
Introduction
Introduction The fifth finger short bend is one of the common symptoms of Down syndrome. Down syndrome, or trisomy 21 syndrome, is also known as congenital or Down syndrome. It is the earliest identified chromosomal disease. 60% of children have abortion in the early stage of the fetus, and the survivors have obvious Intelligent backwardness, special face, growth and development disorders and multiple deformities.
Cause
Cause
(1) Causes of the disease
The incidence of Down's syndrome is related to the age of maternal pregnancy. It is an abnormality of chromosome 21, and there are three types of trisomy, translocation and chimerism. High maternal age, egg aging is an important reason for the absence of separation.
(two) pathogenesis
The trisomy can be isolated from chromosome 21 of the meiotic phase of the parental germ cell. The mechanism of its occurrence is due to the fact that the germ cells of the parent (mostly the mother) are not separated when the meiosis occurs. The older the pregnant woman, the more likely it is that Down syndrome will occur. In a family study of normal diploid parents with 21-trisomy, it was found that the chimeric 21-trisomy cell line in parental germ cells and the single parental dimer of maternal chromosome 21 also occurred in 21-trisomy. the reason. The translocation type can be inherited by one of the parents for the 21st chromosome balance translocation carrier. Except for chromosomal translocation, the karyotypes of peripheral blood lymphocytes in both parents were mostly normal. The key part of chromosome 21 that produces the phenotypic characteristics of Down's syndrome is 21q22.1~q22.2, and the 21 parts of the trisomy that do not include this zone do not present Down syndrome.
Examine
an examination
Related inspection
Abdominal vascular ultrasound examination of bone and joint MRI
The main characteristics of children with Down syndrome are mental retardation, physical retardation and special face. Children with wide eye distance, low flat nose, small eye cracks, oblique outer side of the eye, inner sacral skin, small outer ear, hard sputum narrow, tongue often stick out of the mouth, more drooling; short stature, head circumference smaller than normal, bone age Often behind the age, the teeth are delayed and often misplaced, the hair is soft and less, the limbs are short, the joints can be excessively bent due to the relaxation of the ligaments, the fingers are short and the small points are curved inside.
The characteristics of the skin texture are: through the hand, the angle of the aid increases, the 4th and 5th fingers increase the squat, the bow of the foot and the bow of the thumb and the finger of the 5th finger have only one pleat.
The child has a distinctly special face at birth and often presents with problems and feeding difficulties. With the increase of age, its intelligent low performance is gradually obvious, and the movement development and sexual development are delayed. About 30% of children have other malformations such as congenital heart disease. Due to low immune function, it is prone to various infections, and the incidence of leukemia is also increased by 10 to 30 times. If you live to adulthood, symptoms of Alzheimer's disease often appear after the age of 30.
Diagnosis
Differential diagnosis
The disease should be differentiated from congenital hypothyroidism. The latter can have symptoms such as lethargy, crying hoarseness, feeding difficulties, abdominal distension, constipation after birth. The tongue is large and thick, but there is no special face of this disease. Serum TSH, T4 and karyotype analysis can be detected for identification.
