You have probably known someone with Turner syndrome (TS), whether you knew it or not. This condition affects 1 in 2,000 girls and adult women. The diagnosis may be evident at birth, but sometimes it eludes detection until much later. The condition is the result of a random mutation of one of a woman’s two X chromosomes that happens at conception. There is an absence of all or part of the second X chromosome in some or all cells of the body. In many cases, this abnormality results in miscarriage. Very few fetuses survive to birth. These survivors comprise the 1 in 2,000 statistic above.
Signs and symptoms of TS at birth are broad. Some girls possess characteristic physical findings resulting in a prompt diagnosis. These include certain heart abnormalities, slightly smaller birth weight, a slight eye droop, body swelling, a widened neck, and low set ears and hairline. However, these features may be absent or very mild. A missed diagnosis is very possible in these cases.
Occasionally, the fingernails and toenails are upturned or even underdeveloped. The top of the mouth, called the palate, may arch upward and not have a normal flattened appearance. Children with TS may have more pigmented moles on the skin. They may have poor enamel strength leading to frequent cavities.
In the first years of life, girls with TS may experience frequent ear and sinus infections. These can lead to hearing loss if not effectively managed. Since other toddlers may also have frequent ear infections, this TS sign might elude detection by the doctor. Kidney abnormalities in TS may present as frequent urinary tract infections.
The most common TS finding is short stature. If untreated, a girl with TS will have an average adult height of 4 feet, 8 inches. This is because an important growth gene located on the missing or partial X chromosome (called SHOX) is lost or damaged.
Since girls require two normal X chromosomes to maintain healthy ovarian function, girls with TS often experience infertility. If the ovaries fail before adolescence, the girl will not go through normal puberty. Failure to start puberty on time can result in a TS diagnosis in some girls.
Girls with TS may experience educational difficulties, social issues, and anxiety. Although intelligence in TS is normal, they may struggle with certain subjects. However, there is a tendency for girls with TS to have warm and caring personalities. Other signs and symptoms of TS include high blood pressure, Type 2 diabetes, low thyroid, and osteoporosis (as adults).
As a physician who has diagnosed and cared for many children and teens with TS, I can attest that each case presents in a unique way. Sometimes the only suspicion of the condition is poor growth. A TS diagnosis requires a blood test called a karyotype. This test counts the chromosomes and looks at their structure. Girls with TS can have many different karyotype patterns. They all have some form of damage to their second X chromosome.
Once diagnosed, treatment involves looking for conditions listed above that might coexist and require treatment. For instance, growth hormone by daily injection can improve adult height effectively if started early enough. Many girls will also require lifelong female hormone therapy to start and complete proper pubertal development. Hormone replacement therapy maintains proper adult hormone levels and physical appearance.
Dr. Stephen Ponder is a pediatric endocrinologist at Baylor Scott & White McLane Children’s.