Sensenbrenner Syndrome

At a glance

Ciliopathy. Autosomal recessive disorder characterized by dolichocephaly, sagittal suture synostosis, sparse and slow-growing fine hair, hypertelorism, nystagmus, taurodontia, dental fusion, anteverted nares, brachydactyly, clinodactyly, narrow thorax leading to respiratory problems, and mild mental retardation.

Synonyms

Cranioectodermal Dysplasia; Levin Syndrome I.

Incidence

Around 40 patients have been reported.

Genetic inheritance

Autosomal recessive.

Pathophysiology

Mutations in four different genes are responsible: IFT122 on 3q22.3, WDR35 on 2p24.1, WDR19 on 4p14, and IFT43 on 14q24.3. Products are part of the intraflagellar transport complex A (IFT-A). IFT-A is required for retrograde flagellar transport in cilia.

Diagnosis

Clinical and radiological features. Radiological features include generalized osteoporosis with shortening of the ribs and long bones, particularly the humeri and fibulae; distal phalanges are short and broad; the epiphysis of long bones tends to be flattened; the vertebral bodies have convex upper and lower surfaces with short pedicles in lumbar spine area; the skull shows dolichocephaly, in association with premature fusion of sagittal synostosis.

Clinical aspects

Craniofacial: dolichocephaly is most characteristic (in some cases, it is caused by sagittal suture synostosis); hypertelorism; epicanthic folds; broad nasal bridge; anteverted nares; everted lower lip; high-arched palate. Chest: narrow thorax, mild pectus excavatum. Limbs: short, bowed limbs with rhizomelia (arms more affected); brachydactyly; single palmar crease, short, broad toes. Ectodermal: nails are short and stubby; scalp hair is fine, sparse, slow-growing with absence of central pigment core on microscopy; teeth are few, small, and widely spaced. Other reported features include congenital heart disease with cor triatriatum in one case. A cor triatriatum is an anomaly where the pulmonary vein is not attached to the left atrium, but rather empties in an accessory chamber superior to the left atrium, simulating a mitral valve stenosis. Ocular: visual impairment, myopia, nystagmus, and retinosis pigmentosa. Chronic renal failure in 70% of patients. All patients have normal intellect but growth is mildly retarded. Most of the premature deaths are respiratory related.

Precautions before anesthesia

Patients must be assessed for respiratory function with examination, chest radiography, arterial blood gas analysis, and oxygen requirements (multiple chest infections are frequent). Assess for cardiac defect with examination, chest radiography, ECG, echocardiogram, and cardiac catheterization when suspected. Biochemistry test, including potassium, creatinine, and urea, must be obtained to assess renal function. Abnormal calcium homeostasis has been reported.

Anesthetic considerations

No reported experience. Position head appropriately for tracheal intubation considering the abnormally shaped head, frontal bossing, and occipital protuberance. Potential for ventilation problems in presence of a narrow thorax and frequent respiratory infections. Intravenous access may be difficult with abnormal limbs.

Pharmacological ...