Sanjad-Sakati Syndrome

At a glance

Genetically transmitted polymalformative syndrome characterized by hypoparathyroidism, growth retardation, developmental delay, seizures, and facial dysmorphism (eg, micrognathia).

Synonyms

Hypoparathyroidism with Short Stature, Mental Retardation, and Seizures; Kalam Hafeez Syndrome; Richardson-Kirk Syndrome; Middle-East Syndrome; Hypoparathyroidism-Mental Retardation-Dysmorphism Syndrome; Hypoparathyroidie Retard Mentale et Dysmorphisme (French).

History

First described in the Kingdom of Saudi Arabia in 1988 by S. Sanjad and S. Sakati. Since, it has been reported in Qatar, Kuwait, and Omani. It is possibly present also elsewhere in the Middle East and Arabian Gulf Countries.

Incidence

Very rare. More frequently reported in the Middle East and the areas of the Arabian Gulf (incidence of 7-8/100,000 births in Kuwait).

Genetic inheritance

Autosomal recessive mutation of the TBCE gene on short arm of chromosome 1 at position 42-43 (1q42-q43). Consanguinity frequent.

Pathophysiology

Virtually undetectable levels of parathyroid hormone resulting in hypocalcemia associated with hypophosphatemia. Growth hormone and insulin-like growth factor levels were also found to be low in affected children. Treatment with human growth hormone produced a rapid increase in the height and weight of one affected 5-year-old child. It was speculated that the hypothalamus plays a role in the regulation of both parathyroid hormone and growth hormone.

Diagnosis

Clinical features plus the onset of hypocalcemia with very low parathyroid hormone levels, usually in the newborn period. Usually consanguineous parents.

Clinical aspects

Early onset hypocalcemia, which may be asymptomatic, associated with hyperphosphatemia. Very low parathyroid hormone levels, and possibly low growth hormone and insulin-like growth factor. Consequently, patients have retarded growth (>2 SD [standard deviations] below the mean). Facial dysmorphism is very consistent, especially within families with more than one affected child: microcephaly, deep-set eyes, depressed nasal bridge with beaked nose, long philtrum, thin upper lip, micrognathia, and large, floppy ear lobes. Most children have skeletal defects, such as medullary stenosis. Dental problems are common and include hypomineralization, caries, and dental agenesis. Increased susceptibility to infections with recurrent respiratory infections. Reported ocular anomalies (progressive corneal opacity, tortuous retinal vessels). Developmental delay is common. Seizures may occur. Reduced numbers of some T-cell subsets have been detected in some patients, but immunological function appears normal.

Precautions before anesthesia

An anesthesiology consultation is recommended before elective surgery. Detect and treat hypocalcemia/hyperphosphatemia. Evaluate the patient carefully for potential difficult tracheal intubation.

Anesthetic considerations

A difficult direct laryngoscopy and tracheal intubation may be expected, especially in patients with micrognathia. If so, spontaneous respiration should be maintained until the airway is secured and lung ventilation is confirmed. Endotracheal tubes smaller than predicted for age may be required. ...