Big face

Introduction Fragile X syndrome This patient has a tall body with a long face and long ears. The prevalence of this disease is about 0.073% to 0.092%. It is another chromosomal disease involving mental retardation that is second only to congenital.

Cause

The disease was identified as a familial chain mental retardation in 1969. The X-chromosome has a narrowed region at the distal end of the long arm, located at Xq27 or Xq28. Recently, molecular genetics found the mental retardation (FMR-1) gene of Fragile X syndrome. Because CCG trinucleotide expansion is repeated, normal human repeats are less than 30, while patients reach 230, and often reach more than 1000. If it is greater than 50 ~ 200, the disease can be suspected.

an examination

Related inspection

Chromosome international standard intelligence test

The prevalence of this disease is about 0.073% to 0.092%. It is another chromosomal disease involving mental retardation that is second only to congenital. 21 three signs are single, sporadic, and Fra X is heritable, usually male is homozygous, is the onset, women are usually not expressed as heterozygous carriers, estimated to be 1/2500 ~ 1 in male infants /1000, 1/2000 in women, X-linked mental retardation is about 1/600, and at least 1/4 is fragile X syndrome.

FZ-1 gene mutation analysis and Xq27.3 fragile site examination were performed in 233 primary MR patients in low-intelligent populations, and 9 were positive, accounting for 3.86% (Zhao Pei, 1998). The patient has a tall body, large face and long ears, prominent forehead and tibia, and large testicles can be seen after puberty, with a volume of 24 to 61 ml. Language barriers are prominent, language development is delayed and language quality is abnormal, and there may be repeated language, imitating language or chattering with impatience and impulsivity, but the delay in language development is commensurate with mental retardation. Some patients may exhibit hyperactivity or passive negative behavior, and some have self-harm behavior and autism-like symptoms. Some cases may be associated with neurological abnormalities, with 15% of patients with epilepsy.

Differential diagnosis

The auricle becomes larger: the cyst of the abdomen of the ear is unexplained. Because of its absence of epithelial layer, it is called a pseudocyst. The majority of patients are male, and the age of onset is generally 30 to 40 years old, mostly occurring in one side of the auricle.

Facial malformations: A variety of head and face deformities are caused by abnormalities in the first and second thoracic ridges that form the facial bones and ears at 2 months of gestation. These malformations include cleft lip and palate: Treacher Collin (mandibular dysplasia), Goldenen (eye, ear, vertebral hypoplasia), Pierre Robin and Warardenbury syndrome; increased distance between organs, external and middle ear malformations. Most infants with head and face deformities have normal intelligence and development.

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