Overview Congenital cranioclavicular hypoplasia is a congenital generalized membranous ossification insufficiency, which is mainly characterized by cranial parietal and clavicular dysplasia, and may involve multiple or single bones. Etiology The cause of this disease is unknown, it is autosomal dominant, and its marquee gene has been localized to 6P21. About 2/3 of the cases have a family history, and 1/3 of the cases are disseminated, with no significant difference between genders, and the disease can develop at any age, but the onset of the disease is most pronounced in the first 2 years of life. Clinical manifestations The lesions involve a wide range of surfaces, in addition to the main involvement of the clavicle and skull, there may also be incomplete pelvic ossification, spinal deformity and flattening, absence of attachments, or occult spina bifida, and the teeth, as well as the carpal bones, slow calcification of the bone, and so on. Symptoms mainly include a large head and small face, sunken shoulders, narrow chest, relatively large front passenger, top of the head and jaw, and partially or completely missing clavicle, usually symmetrical. Sometimes combined with muscle abnormalities, such as the absence of the anterior part of the deltoid muscle and the clavicle part of the trapezius muscle. Diagnosis The diagnosis is easily made by the typical deformities of the head and face and by what is seen on radiographs. Examination The disease is mainly examined by X-ray, and some scholars categorize it into three types according to the presence or absence of genetic relationship and the severity of symptoms: 1. The first type is the standard type:: there is a family genetic relationship, and the skull, clavicle and pelvis are all involved. The X-ray presentation is typical. For example, unilateral or bilateral clavicles are partially or completely absent, cranial ossification is incomplete, fontanel is large, cranial suture is not closed, sometimes the sternal stalk is absent, and spina bifida is extensive. The second type is the familial type: there is a family genetic relationship, but the skull is not involved. The third type is the disseminated type: there is no family genetic relationship. Complications The disease may be associated with chondrodystrophies, which in severe cases may include dwarfism, impaired development of the situs and pubis, spina bifida, and delayed development of the carpal bones, etc. In some cases, the disease may also be associated with muscular abnormalities, such as absence of the anterior portion of the deltoid muscle and the clavicular portion of the trapezius muscle. Therapeutic measures The clinical symptoms of this disease are relatively few, and the diagnosis of typical cases is relatively clear. Although the deformity is complicated and the appearance is ugly, most of the affected children have normal intelligence, and their life and labor are not affected, which seldom cause serious dysfunction, and do not need any special treatment, unless the combined limb deformity affects the activity, or the clavicular stump occasionally compresses the brachial artery or brachial plexus nerves, and the effect of surgical resection of clavicular stump to relieve the compression is satisfactory. Preventive health care This disease is a congenital disease, so there is no effective preventive measures, early diagnosis and early treatment is the key to the prevention and treatment of this disease. Early diagnosis and treatment is the key to preventing and treating this disease. When diagnosing, attention should also be paid to differentiating the disease from other diseases with similar symptoms, so as to give the children the correct treatment.