Additional Tunisian patients with Sanjad-Sakati syndrome: A review toward a consensus on diagnostic criteria

Abstract

Background and objectives: Sanjad-Sakati syndrome (SSS; OMIM 241410) is a rare autosomal recessive disorder found almost exclusively in people of Arab origin. It is characterized by congenital hypoparathyroidism, severe prenatal and postnatal growth retardation, and distinct facial dysmorphism. The molecular pathology of this syndrome was shown to be due to a mutation in the tubulin-specific chaperone E (TBCE) gene in chromosomal area 1q42-q43. We aimed to detect and confirm the common mutation responsible for SSS in Tunisian patients and review the literature in order to create a set of clinical diagnostic criteria that might provide appropriate indications for molecular testing.

Methods: Three Tunisian patients with clinical feature of SSS were examined via direct Sanger sequencing of exon 3 of the TBCE gene.

Results: Mutation analysis of the TBCE gene revealed the common 12-bp (155-166del) deletion in three new patients, thus raising the number of reported SSS patients to 73. Reviewing the literature, we suggest a scoring system that assigns one point each for major criteria and one half point for minor criteria.

Interpretation and conclusions: SSS is an autosomal recessive disorder found in the Middle Eastern population with an estimated incidence of 1 per 40,000-100,000 live births in Saudi Arabia. Reviewing the literature on both its clinical and biochemical characteristics, we suggest for the first time, based on defined major and minor SSS criteria, a clinical scoring system for the diagnosis of SSS. On the one hand, an established scoring system will provide appropriate indications for molecular testing and, on the other hand, reviewed data on SSS will help delineate the phenotype and draw a distinction between differential diagnoses.

Keywords: Diagnostic criteria; Dysmorphism; Growth retardation; Hypoparathyroidism; Tunisia.