Small jaw

Introduction The jaw is seen in the trisomy 18 syndrome, also known as Edwrd syndrome. The incidence rate of neonates is 1/3500~1/8000, and the ratio of male to female is 1:4. The incidence rate is related to the increase of maternal reproductive age. 18-trisomysyndrome (Edwards syndrome) is the second common trisomy of the common chromosome. In 1960, Edwards and others first reported a case of multiple malformations. One extra chromosome was identified by chromosome examination, which is considered to be chromosome 17. Many scholars have successively reported similar observations, confirming that these clinical syndromes are related to chromosome 18 abnormalities. There have been hundreds of reports so far. The main clinical manifestations were multiple malformations, more than a few weeks after birth.

Cause

The incidence of this disease in newborn babies is 1:3500 ~ 8000, mostly in older parents, mothers, 52% over 35 years old. Girls have a higher incidence than boys, about 3 to 4:1. The incidence of conceiving mothers in autumn and winter is higher, and the incidence increases with the growth of parents during childbirth. The average age of the mother is 32.5 years old, with two peaks of 25 to 30 years old and 40 to 45 years old. The average age of the father is 34.9 years old. A small number of patients have nothing to do with the age of their parents. The mother's average pregnancy is 42 weeks, often expired, and the mother feels weak fetal movement during pregnancy, more amniotic fluid, small placenta, often only one umbilical artery.

an examination

Related inspection

Maxillofacial examination temporomandibular joint examination blood routine amniocentesis cell culture chromosome examination chromosome

The trisomy 18 has a wide range of malformations, reaching more than 115 species, but not all malformations are present in every patient. There was no obvious abnormality in the first time, but careful observation revealed abnormal bone proportion, prominent occipital bone, short sternum, and small pelvis. Neonatal early muscle tension is low, and later muscle tension is increased, thus limiting the ability of the thigh to fully abduct. The pathology of the fingers described in the previous section is the most obvious feature of the disease. Fingerprint bows are often more than six, such as the appearance of fingerprint arched lines, can be highly suspected as 18 trisomy syndrome. For children who are older and have intelligence and developmental disorders with multiple malformations. Consider the possibility of having this disease. Individual cases may have no significant physical characteristics during the first few months of life.

The clinical manifestations of trisomy 18 are highly variable, and none of the malformations are unique to trisomy 18. Therefore, it is not possible to make a diagnosis based on clinical abnormalities, and a cell chromosome examination must be performed.

Differential diagnosis

Symptoms are more common in the 18 trisomy syndrome clinically identified with the following diseases.

1.13 trisomy syndrome

There are many clinical manifestations that can be found in Trisomy 13 and Trisomy 18. Most cases have their own faces, and can be diagnosed quickly, but the facial performance of a small number of patients is not prominent, and it is difficult to identify at one time. 13 trisomy syndrome is characterized by small head, forehead retraction, narrow stenosis, common ulcer of the scalp of the skull, small eyes, too close or widened distance between the eyes, iris defect, low ear position, cleft lip, cleft palate, often Capillary fistula, over-exposed nails, multi-finger, horseshoe inversion, S-shaped bow-shaped pattern on the metatarsal side. In addition to the absence of iris defects, the trisomy 18 can also have the above-mentioned manifestations of eyes, ears and hands and feet in a few cases. The chromosome must be checked to determine the diagnosis.

2. Multiple anomaly syndrome (multiple anomalysyndrome)

The multiple malformation syndrome described by Smith in 1964 has many deformities similar to trisomy 18, such as developmental disorders, small heads, high muscle tone, drooping eyelids, upturned nostrils, through hands, and far axis, The second to third toe and toe, the boy has hypospadias and cryptorchidism; the position of the hand is similar to the trisomy 18 and the pelvis is small. However, this multiple malformation has no sternal shortness and ventricular septal defect and the arched fingerprint does not increase; the cell chromosome examination is normal, and the trisomy 18 syndrome can be excluded. This syndrome is thought to be caused by a mutation in the chromosomal gene.

The trisomy 18 has a wide range of malformations, reaching more than 115 species, but not all malformations are present in every patient. There was no obvious abnormality in the first time, but careful observation revealed abnormal bone proportion, prominent occipital bone, short sternum, and small pelvis. Neonatal early muscle tension is low, and later muscle tension is increased, thus limiting the ability of the thigh to fully abduct. The pathology of the fingers described in the previous section is the most obvious feature of the disease. Fingerprint bows are often more than six, such as the appearance of fingerprint arched lines, can be highly suspected as 18 trisomy syndrome. For children who are older and have intelligence and developmental disorders with multiple malformations. Consider the possibility of having this disease. Individual cases may have no significant physical characteristics during the first few months of life.

The clinical manifestations of trisomy 18 are highly variable, and none of the malformations are unique to trisomy 18. Therefore, it is not possible to make a diagnosis based on clinical abnormalities, and a cell chromosome examination must be performed.

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