Often cited as one of the most common chromosomal abnormalities in females, Turner
syndrome (TS) affects up to 1 in 2500 live births per year. Recent international efforts
have been made to address medical advances and provide updated consensus guidelines
(10.1542/peds.2017-2626) for the management of patients with TS. These guidelines, which are endorsed by
the American Academy of Pediatrics, are far more comprehensive from those previously
published in 2007 and offer new recommendations regarding diagnosis, the management
and frequency of screening for aortic dilation, and the routine care of girls and
women with TS.
Though a karyotype remains the gold standard for diagnosis, the updated guidelines
provide more specific indications as to when to pursue chromosomal analysis. In accordance
with prior recommendations, it is currently suggested that TS be considered in the
evaluation of any patient with unexplained poor growth or pubertal delay. However,
these updated guidelines also list other solitary features (such as a couple with
infertility or fetal cystic hygroma) that are indications for karyotype analysis.
Furthermore, these new recommendations advise chromosomal analysis if two or more
of the following features are present: renal anomalies, Madelung deformity of the
wrist (premature closure of the radial epiphysis resulting in bowing of the radial
shaft and dorsal sublaxation of the distal radioulnar joint), a history of neuropsychiatric
issues, multiple typical or melanocytic nevi, or nail hypoplasia. Given the myriad
of presenting signs and symptoms in TS, this change should be beneficial to practitioners
as it provides specific indications for further diagnostic evaluation.
Perhaps the most significant update to the prior 2007 guidelines is a set of novel
algorithms for the screening and management of aortic dilation in patients with TS.
The risk of aortic dissection is well established in TS, occurring in 40 of 100,000
people as compared to 6 out of 100,000 in the general population. Given that the prevalence
of aortic dilation is as high as 42%, all patients with TS should receive an echocardiogram
at the time of diagnosis. Patients should also undergo cardiac MR or CT when old enough
to tolerate without sedation. While these recommendations are unchanged from prior,
the new guidelines provide detailed algorithms that determine the frequency of screening
for aortic dilation, as well as indications for medical and surgical management. For
patients less than 16 years of age, the algorithm uses a TS specific Z-score, as measured
with echocardiography, to stratify patients based on their risk of dissection. For
those over the age of 16, the algorithm risk stratifies patients based on their Aortic
Size Index (ASI), which represents the absolute aortic diameter divided by the body
surface area. Based on their individualized risk, which also takes into account a
history of bicuspid aortic valve or hypertension, patients will then undergo screening
with echo or cardiac MR every year, every 2 - 3 years or every 3-5 years. If no cardiovascular
disease is present, current recommendations suggest screening every 5 years in children,
every 10 years in adults, and prior to pregnancy. Recommendations for sports participation
are also provided, depending on the degree of aortic dilation.
New recommendations for the routine care of patients with TS includes annual diabetic
screening with a hemoglobin A1C after age 10, biennial screening for vitamin D deficiency
starting at age 9, and biennial screening for celiac disease after age 2. In keeping
with prior recommendations, it is still advised that patients undergo formal audiology
testing every 5 years and are seen by a pediatric ophthalmologist between 12 and 18
months of age.
While there are still many questions to answer, these guidelines provide significant
advances in the care and management of girls and women with TS.