Mildly obese to morbidly obese children are also more likely to begin puberty earlier than children of normal weight. Variation in genes related to obesity such as FTO or NEGRI have been associated with earlier onset of puberty. Children whose parents started puberty at an earlier age were also more likely to experience it themselves, especially in women where onset of menstruation correlated well between mothers and daughters and between sisters. Causes
Pubertal delay can be separated into four categories from most to least common:

Constitutional and physiologic delay
Children who are healthy but have a slower rate of physical development than average have a constitutional delay with a subsequent delay in puberty. It is the most common cause of delayed puberty in girls (30%) and even more so in boys (65%). It is commonly inherited with as much as 80% of the variation in the age of onset of puberty due to genetic factors. These children have a history of shorter stature than their age-matched peers throughout childhood, but their height is appropriate for bone age, meaning that they have delayed skeletal maturation with potential for future growth.It is often difficult to establish if it is a true constitutional delay of growth and puberty or if there is an underlying pathology because lab tests are not always discriminatory. In absence of any other symptoms, short stature, delayed growth in height and weight, and/or delayed puberty may be the only clinical manifestations of certain chronic diseases including coeliac disease.
Children with delayed puberty also display decreased academic performance in their adolescent education, but changes in academic achievement in adulthood have not been determined.There is conflicting evidence as to whether or not children with constitutional growth and pubertal delay reach their full height potential. The conventional teaching is that these children catch up on their growth during the pubertal growth spurt and just remain shorter before their delayed puberty starts. However, some studies show that these children fall short of their target height from about 4 to 11 cm. Factors that could affect final height include familial short stature and pre-pubertal growth development.Pubertal delay can also affect bone mass and subsequent development of osteoporosis. Men with delayed puberty often have low to normal bone mineral density unaffected by androgen therapy. Women are more likely to have lower bone mineral density and thus an increased risk of fractures as early as even before the onset of puberty.Furthermore, delayed puberty is correlated with a higher risk in cardiovascular and metabolic disorders in women only, but also appears to be protective for breast and endometrial in women and testicular cancer in men. See also
Developmental milestones
Endocrinology
Puberty
Constitutional growth delay
Hypogonadism
Kallmann syndrome
Turner syndrome
Klinefelter syndrome

References


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