Normal Stature and Causes of Excessive Variations

Built is the skeletal structure in relation to age and sex of the individual as compared to a normal person.

Tall Stature

A person considered to be tall when the height is greater than 2 standard deviation above the mean for the age. Gigantism is the term applied when the patient’s height is greatly in excess of the normal for his age.

There is no fixed height to constitute a giant, but in adults, it is applied for individuals with a height of more than 6 ½ ft.

Causes of Gigantism

1. Simple or primary gigantism: Racial, familial or constitutional.
2. Endocrine: Hyperpituitarism, hypogonadis,.
3. Genetic: Klinefelter’s syndrome.
4. Metabolic: Marfan’s syndrome, homocystinuria.
5. Miscellaneous: Cerebral gigantism, overeating.

Constitutional

Usually in constitutional tall stature the parents are also tall. q

Hyperpituitarism

In thisthe patient is very tall but with normal body properties. However, the features are coarse with increased heel pad thickness. There may be evidence of raised intracranial tension.

Cerebral Gigantism

Children with cerebral gigantism (Soto’s syndrome) have a large elongated head, prominent forehead, large ears and jaws, elongated chin, antimongoloid slant to the eyes and coarse facial features. They have subnormal intelligence and impaired coordination. The cause of this disorder is not known.

Sexual Precocity and Virilizing Disorders

In these children, acceleration of linear growth occurs simultaneously with signs of premature sexual development or inappropriate virilization. This disorder may be due to congenital adrenal hyperplasia, adrenal tumor, gonadal tumor or premature secretion of gonadotropic hormones. The bone age is usually advanced so that the adult stature may be diminished.

Marfan’s syndrome

These patients are tall with long limbs, narrow hands, long slender fingers (arachnodactyly), hyperextensible joints, dislocation of the lens, high arched plate, kyphoscoliois, arm span greater than the height and the lower segment more than the upper segment.

Homocystinuria

This condition resembles Marfan’s syndrome.

Klinefelter’s Syndrome

1. Lower segment more than the upper segment.
2. Gynecomastia
3. Small, firm testes, azoospermia.
4. Chromation (Barr) body usually present. (Some may be chromatin negative).
5. Mental retardation
6. Associated with Mongolism and Leukemia.
7. Chronic pulmonary disease, varicose veins and diabetes are more common.

Dwarfism

Dwarfism is the term applied when the patient’s height is far less than normal for his age and sex. It is usually applied for adults below 4 ½ ft. in height.

Causes

1. Hereditary
2. Chromosomal: Turner’s syndrome, Down’s syndrome, etc.
3. Constitutional delayed growth and puberty.
4. Nutritional: Malnutrition, malabsorption, rickets
5. Endocrine: Hypopituitarism, hypothyroidism, excessive androgens and glucocorticoidism, congenital adrenal hyperplasia, insulin deficiency
6. Skeletal: Achondroplasia, spinal deformities
7. Systemic diseases: Renal tubular acidosis, uremia, congenital cyanotic heart disease, cirrhosis of liver, etc.

Hereditary

In hereditary short stature there is no endocrine abnormality. The bone age and the dental age are normal. Although they are short, they grow at a constant rare of 4-5 cms, a year and they have normal body proportions for age. This may be either genetic (if there is a family history of short stature), or primordial (if there is no family history of short stature).

Constitutional delayed growth and puberty

This disorder is common among adolescent boys. There is no true endocrine deficiency. They grow at a constant rate of about 4 cm a year but their bone age and dental age are delayed by about 2 years. Often there is a history of delay in growth and pubertal development in the father and other male relatives.

Turner’s syndrome

These children are predominantly girls. They have agenesis of their gonads. The chromosomal pattern is 45+XO. They have a characteristically short webbed neck, low hair line, square and shield-like chest, cubitus valgus and mental retardation. Although short, they grow at the rate of 4 cm each year with normal bone age and dental age but absent pubertal growth spurt, so that during adolescence, the skeletal age is delayed due to the absence of sex hormones (streak ovaries).

Hypopituitarism

These children have the skeletal age and the dental age delayed by more than 2 years. The growth rate is less than 4 cm/year. The ratio of the upper segment and the lower segment is normal.

Hypothyroidism

These children have mental, dental and skeletal retardation since birth. There would be course dry skin and constipation. Their body proportion is infantile i.e., upper segment is more than lower segment.

Achondroplasia

Achondroplasia dwarfs have short limbs resulting in short stature. Hence, the lower segment is always less than the upper segment. Their mental and dental ages are normal and so are the endocrine functions.

Systemic disease

Most chronic systemic disease can cause growth failure during childhood. These illnesses can be recognized by their own specific clinical features and growth failure is a secondary problem.