Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the bodys tissues and form.Malnutrition is a category of diseases that includes undernutrition and overnutrition. Undernutrition is a lack of nutrients, which can result in stunted growth, wasting, and underweight. A surplus of nutrients causes overnutrition, which can result in obesity. In some developing countries, overnutrition in the form of obesity is beginning to appear within the same communities as undernutrition.Most clinical studies use the term malnutrition to refer to undernutrition. However, the use of malnutrition instead of undernutrition makes it impossible to distinguish between undernutrition and overnutrition, a less acknowledged form of malnutrition. Accordingly, a 2019 report by The Lancet Commission suggested expanding the definition of malnutrition to include "all its forms, including obesity, undernutrition, and other dietary risks." The World Health Organization and The Lancet Commission have also identified "[t]he double burden of malnutrition," which occurs from "the coexistence of overnutrition (overweight and obesity) alongside undernutrition (stunted growth and wasting)." Prevalence
It is estimated that nearly one in three persons globally has at least one form of malnutrition: wasting, stunting, vitamin or mineral deficiency, overweight, obesity, or diet-related noncommunicable diseases. Undernutrition is more common in developing countries. Stunting is more prevalent in urban slums than in rural areas. Studies on malnutrition have the population categorised into different groups including infants, under-five children, children, adolescents, pregnant women, adults and the elderly population.
Disruption of these pathways leads to abnormal bone and cartilage formation causing acrania and multiple other craniofacial patterning problems. Genetic counseling
Little genetic counseling can be offered for acrania because the genetic origins are not fully understood. In order to make genetic counseling for families easier this disease is often differentially diagnosed with other diseases that can occur at the same time such as anencephaly and acalvaria, though these diseases may not always occur simultaneously. Recurrence rates are extremely low, so genetic counseling is not always necessary. Amniotic band syndrome
During amniotic band syndrome (ABS), fibrous bands may entrap various parts of the developing fetus causing malformations. When these fibrous bands form around the developing skull, the bones will not form properly. ABS occurring in the developing brain neural tissue is one cause of acrania. When ABS is the cause of acrania the fibrous bands cannot be detected through ultrasound. Mechanism
During the fourth week of human development the neuropore in a normally developing fetus closes. When this process is either interrupted or never initiated, acrania occurs. The desmocranium becomes a membranous coverage instead of forming the epidermis of the scalp. Whether from being blocked by amniotic bands or by just not initiating, the migration of mesenchyme under the ectoderm does not occur. Because this migration does not occur, the skull, and all involved muscles, are never formed. Without the presence of the neurocranium, the brain fails to separate into two separate lobes.