(X0 syndrome, monosomy X, Bonnevie-Ullrich syndrome)

Prevalence: 1/2,000 to 1/3,000 female births. Gonadal dysgenesis where the caryotype is classically 45, X0 (80 %) but sometimes 46X,Xp- or 46X,Xq - (5 %) or in mosaics (15 %).

 
Association of:

-        moderate short stature (often treatment with synthetic growth hormone), with a triangular broad chest and widely spread nipples

-        dysmorphism: ptosis,  low set ears, high arched palate, short neck with pterygium colli (sequelae of the cervical hygroma present in utero in the X0 forms), micrognathia,

-        lymphedema of the dorsal face of the hands and feet, often present at birth and during early infancy

-        cubitus valgus, scoliosis 

-        premature ovarian failure with absence of puberty if no substitutive treatment is started

In 40-50 % of cases, a cardiovascular anomaly is present:

-         congenital heart disease: coarctation of the aorta, bicuspid aorta valve; more rarely ASD, VSD, anomalous pulmonary venous return

-         progressive dilatation of the ascending aorta and dissection of the aorta especially in case of monosomy X0, which may require treatment with a β-blocker or angiotensin II receptors antagonist

-         high blood pressure: very frequent, with absence of the usual nocturnal decline in BP.

One can also observe: hypothyroidism; bone deformities (scoliosis, osteoporosis); diabetes type 1 or 2 in adulthood, a 'horseshoe' kidney, an increased risk of IBD, and dermatological pathologies (numerous pigmentary nevi, psoriasis, alopecia)

Anesthetic implications: 

check blood pressure; echocardiography; risk of difficult intubation, risk of bronchial intubation. Check thyroid function.

References : 

-        Mashour GA, Neelakantan S, Asquadro MA. 
Anesthetic management of Turner syndrome : a systematic approach. 
J Clin Anesth 2005; 17: 128-30.

Updated: April 2020