Ullrich-Turner Syndrome

Chromosomal disorder with a specific aspect (pterygium colli short neck and gonadal insufficiency).

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Turner-Varney Syndrome; 45X Syndrome; Bonnevie-Ulrich Syndrome; Monosomy X; XO Syndrome; Turner Syndrome.

X-linked chromosomal disorder resulting from one functional X chromosome. First described by Henry Hubert Turner, American endocrinologist in 1938, in a patient with sexual infantilism, webbed neck, cubitus valgus, and short stature. The genetic basis was recognized in 1959 by C.E. Ford et al.

1:2500 live births in the female gender.

Caused by a defect of one entire chromosome X (50% of patients), mosaicism (20% of patients) or two chromosomes X but one abnormal (30% of patients). Nearly 99% of XO fetuses are aborted. The primary defect is thought to be abnormal development of lymphatic channels in utero, resulting in fetal lymphedema, which prevents normal growth, rotation, and regression of fetal tissues, thus causing the Turner phenotype.

Small stature, short and broad neck, hypoplasia of the cervical vertebrae, pterygium colli, and gonadal dysgenesis are the most frequent and characteristic signs of the disease. Age of onset is variable according to the presentation: infant: lymphedema; childhood: short stature; adolescence: primary or secondary amenorrhea. Risk factors include advanced paternal age (isochromosome X cases) and mother affected with a mosaic or dilational variant of the Turner syndrome. For certitude, the diagnosis can be confirmed using karyotype studies.

Clinical features can concern all systems and part of the bodies: head (micrognathia, midfacial hypoplasia, deepening of the posterior cranial fossa, widely spaced mandible, large ears, blepharoptosis strabismus, epicanthal folds, highly arched palate, occasional cleft palate, premature tooth eruption), skeleton (thin ribs, short metacarpal and metatarsal bones, drumstick distal phalanges, pes cavus, Madelung deformity, cubitus valgus, deformed tibial condyles, hypoplastic and dislocated patellae, faulty fusion of the epiphyses, scoliosis, osteoporosis), cardiovascular system (coarctation of the aorta, dissecting aortic aneurysm, ventricular septal defect, atrial septal defect, dextrocardia, bicuspid aortic valve, hypoplastic left heart), abdomen (prune belly, telangiectases, hemangiomas, intestinal bleeding, protein-loosing enteropathy), genitourinary system (unilateral aplasia or hypoplasia of the kidneys, horseshoe kidneys, malrotation of the kidneys, duplication dysgenesis, and streak gonads), endocrinopathy (hypothyroidism, Hashimoto disease, diabetes mellitus), and skin and dermatoglyphs (puffy hands and feet, pigmented nevi, seborrhea, xerosis, keloid, nail hypoplasia, low hairline, hirsutism). Abnormally placed nipples are also very frequent. Mental retardation, deafness, blindness, anorexia nervosa, amenorrhea, and sterility can occur. This complex polymalformative syndrome benefits of many symptomatic treatments that have greatly improved patients outcome. Features vary with age of presentation: newborn: lymphedema of the hands and feet, small for age and excessive skin at nape of the neck; childhood and adolescence: short stature (98% of patients), gonadal dysgenesis (95% of patients), high-arched palate (80% of patients), short neck and low hairline (80% of patients), and broad chest, cubitus valgus, and nail hypoplasia.

Evaluate carefully the cardiac function (clinical, echocardiography, ECG, radionuclide imaging if necessary), renal function (ultrasound, urea, creatinine, electrolytes, CT), airway (clinical, radiographs, fiberoptic endoscopy, CT), and endocrine function (clinical, echography of thyroid). Laboratory investigations should include FT4, T3, glycemia, and urinary electrolytes.

Direct laryngoscopy and tracheal intubation are often difficult because of neck anomalies and micrognathia (fiberoptic intubation may be required) and necessitate to preserve spontaneous ventilation until tracheal intubation is confirmed by the presence of end-tidal carbon dioxide. A laryngeal mask airway should be available in case of failure to intubate the trachea using usual technique. Venous access is sometimes a challenge because of puffy hands and feet. Careful intraoperative positioning is necessary. Intraoperative cardiac monitoring will be adapted according to the existing cardiac anomalies. Pulse oximetry can be perturbed by nail anomalies. Strict supervision of respiratory function is needed after extubation in cases of prune belly.

Intraoperative fluid regimen must take into consideration the renal and cardiac function. Prophylactic antibiotics should be used in cases of cardiac defect.

Noonan Syndrome: This syndrome is not a chromosomal defect, but a genetic disorder involving a gene encoding the nonreceptor protein tyrosine phosphatase SHP2 (maps on 12q24.1). Noonan syndrome bears a lot of similarities with Turner syndrome. The principal differences concern sexual characteristics (female and male in Noonan) and cardiac defects (more often pulmonic stenosis than left-sided cardiac lesions). Hematologic features are frequently observed (abnormal platelet, thrombocythemia, von Willebrand disease, and partial deficiency of factors XI:C, XII:C, and XIII:C).