Down syndrome: Epidemiology, Symptoms,Risk factors & Work-ups
Epidemiology
Down syndrome is a chromosomal disorder. 95% is caused by trisomy 21, 1% by mosaics and 4% by translocation. At present, the proportion of mosaics is known to be slightly higher. In the case of Mosiacs, phenotype appears to be mild but eventually it grows and morphology specific to Down syndrome appears. All chromosomal studies should be performed in all patients suspected of Down syndrome and chromosomal studies should be conducted in their parents to prevent another case of translocation. If parents have Robertsonian translocation of t (21; 21), then the probability of a child being down sydrome is 50%. Current research indicates that targets such as DYRK1A and DSCR1 are the major targets of Down syndrome.
Symptoms
The main symptoms of Down syndrome are very diverse. First, the central nervous system problem. Hypotonia can appear and development is slow. Also, the moro reflex appears weak. Cognitive impairment usually appears and social development is relatively good. However, expressive language presents a great deal of difficulty. There is no behavioral disorder, but abnormal behavior can occur from cognitive impairment. There is no aggressive or self-directed behavior, but attention deficit, high concentration, and repetitive behavior can occur. 18 to 38% of mental illnesses are more severe than those of the general population, but they are relatively less common than those with other mental retardations. Next, we can see craniofacial symptoms. Brachycephaly with flat occiput, flat face, upward slanted palpebral fissures, monkey palms, speckled irises, 3 fontanels, and fontanel may be closed late and frontal sinus and midfacial hypoplasia may appear. It also has a mild microcephaly, a short hard plate, a small nose, a flat nose, and a tongue sticking out. The ears can be small and strange. Cardiovascular anomalies include endocardial cushion defects, ventricular septal defect, atrial septal defect, patent ductus arteriosus, aberrant subclavian artery, and pulmonary hypertension. On the musculoskeletal side, joints and flexion, short neck, redundant skin, short finger and wrist bones, short fifth finger, monkey palm, wide point between first and second toes, pelvic dysplasia, short sternum, two There are sternum manubrium ossification centers. Gastrointestinal symptoms include duodenal atresia, annular pancreas, Tracheoesophageal fistula, Hirschsprung disease, Imperforate anus and cutis marmorta as a skin symptom.
Risk factors
The greatest risk factor for Down syndrome is when the mother is over 35 years of age. The actual incidence of Down syndrome in women before the age of 35 and after the age of 35 is half, because of the high birth rate of women before the age of 35. The prevalence of Down syndrome is examined by pre-examination. When the thickness of the fetal neck is over 3mm through nuchal translucency in 1st trimester, it is suspected of Down syndrome. When using free b-hCG and PAPP-A together, more accurate results are obtained. In addition, the quadruple test can be used to discriminate the 2nd trimeseter. AFP, hCG, uE3, and Inhibin a. In the case of Down syndrome, AFP and uE3 are low and hCG and Inhibin a tend to be high. The diagnosis of Down syndrome can be confirmed by a chromosomal study.
Work-ups
In fact, the symptoms of Down syndrome are very diverse and require periodic follow up. Congenital heart disease is a risk factor for congenital heart disease in about 50% of Down syndrome. As a result, the risk of pulmonary hypertension also increases. Second, we perform tests for various ocular problems - strabismus, cataracts, and nystagmus. It is inspected at birth or at 6 months, and is tested periodically every year. Cataracts occur at 15% and refractive errors occur at 50%. Hearing tests are also performed immediately after birth or at 3 months, with auditory brainstem response or optoacoustic emission testing. If the tympanic membrane is not visible, it is observed until 3 years of age and then observed annually thereafter. Hearing loss can occur in more than 50% to 70% of serous otitis media. The presence of the constipation should be confirmed immediately after birth, in order to identify Hirschsprung disease. Testing for Celiac disease is done at age 2 or when symptoms develop, and tests for IgA and tissue transglutaminase antibodies are performed. Hematologic disease is diagnosed at birth, during puberty, and when symptoms appear, to confirm the risk for neonatal polycythemia, leukemoid reaction, and leukemia. Hypothyroidism is repeated immediately after birth and at 6 to 12 months. In addition, visit-time tests should be performed on obstructive sleep apnea, atlantoaxial subluxation or instability, gynecologic care, recurrent infections, psychiatric and behavioral disorders.
Down syndrome is a chromosomal disorder. 95% is caused by trisomy 21, 1% by mosaics and 4% by translocation. At present, the proportion of mosaics is known to be slightly higher. In the case of Mosiacs, phenotype appears to be mild but eventually it grows and morphology specific to Down syndrome appears. All chromosomal studies should be performed in all patients suspected of Down syndrome and chromosomal studies should be conducted in their parents to prevent another case of translocation. If parents have Robertsonian translocation of t (21; 21), then the probability of a child being down sydrome is 50%. Current research indicates that targets such as DYRK1A and DSCR1 are the major targets of Down syndrome.
Symptoms
The main symptoms of Down syndrome are very diverse. First, the central nervous system problem. Hypotonia can appear and development is slow. Also, the moro reflex appears weak. Cognitive impairment usually appears and social development is relatively good. However, expressive language presents a great deal of difficulty. There is no behavioral disorder, but abnormal behavior can occur from cognitive impairment. There is no aggressive or self-directed behavior, but attention deficit, high concentration, and repetitive behavior can occur. 18 to 38% of mental illnesses are more severe than those of the general population, but they are relatively less common than those with other mental retardations. Next, we can see craniofacial symptoms. Brachycephaly with flat occiput, flat face, upward slanted palpebral fissures, monkey palms, speckled irises, 3 fontanels, and fontanel may be closed late and frontal sinus and midfacial hypoplasia may appear. It also has a mild microcephaly, a short hard plate, a small nose, a flat nose, and a tongue sticking out. The ears can be small and strange. Cardiovascular anomalies include endocardial cushion defects, ventricular septal defect, atrial septal defect, patent ductus arteriosus, aberrant subclavian artery, and pulmonary hypertension. On the musculoskeletal side, joints and flexion, short neck, redundant skin, short finger and wrist bones, short fifth finger, monkey palm, wide point between first and second toes, pelvic dysplasia, short sternum, two There are sternum manubrium ossification centers. Gastrointestinal symptoms include duodenal atresia, annular pancreas, Tracheoesophageal fistula, Hirschsprung disease, Imperforate anus and cutis marmorta as a skin symptom.
Risk factors
The greatest risk factor for Down syndrome is when the mother is over 35 years of age. The actual incidence of Down syndrome in women before the age of 35 and after the age of 35 is half, because of the high birth rate of women before the age of 35. The prevalence of Down syndrome is examined by pre-examination. When the thickness of the fetal neck is over 3mm through nuchal translucency in 1st trimester, it is suspected of Down syndrome. When using free b-hCG and PAPP-A together, more accurate results are obtained. In addition, the quadruple test can be used to discriminate the 2nd trimeseter. AFP, hCG, uE3, and Inhibin a. In the case of Down syndrome, AFP and uE3 are low and hCG and Inhibin a tend to be high. The diagnosis of Down syndrome can be confirmed by a chromosomal study.
Work-ups
In fact, the symptoms of Down syndrome are very diverse and require periodic follow up. Congenital heart disease is a risk factor for congenital heart disease in about 50% of Down syndrome. As a result, the risk of pulmonary hypertension also increases. Second, we perform tests for various ocular problems - strabismus, cataracts, and nystagmus. It is inspected at birth or at 6 months, and is tested periodically every year. Cataracts occur at 15% and refractive errors occur at 50%. Hearing tests are also performed immediately after birth or at 3 months, with auditory brainstem response or optoacoustic emission testing. If the tympanic membrane is not visible, it is observed until 3 years of age and then observed annually thereafter. Hearing loss can occur in more than 50% to 70% of serous otitis media. The presence of the constipation should be confirmed immediately after birth, in order to identify Hirschsprung disease. Testing for Celiac disease is done at age 2 or when symptoms develop, and tests for IgA and tissue transglutaminase antibodies are performed. Hematologic disease is diagnosed at birth, during puberty, and when symptoms appear, to confirm the risk for neonatal polycythemia, leukemoid reaction, and leukemia. Hypothyroidism is repeated immediately after birth and at 6 to 12 months. In addition, visit-time tests should be performed on obstructive sleep apnea, atlantoaxial subluxation or instability, gynecologic care, recurrent infections, psychiatric and behavioral disorders.
