Hypoparathyroidism-Retardation-Dysmorphism Syndrome due to a Variant in the Tubulin-Specific Chaperone E Gene as a Cause of Combined Immune Deficiency.

BACKGROUND: Hypoparathyroidism-retardation-dysmorphism (HRD) syndrome is a disease composed of hypoparathyroidism, growth retardation, severe developmental delay, and typical dysmorphic features caused by the tubulin-specific chaperone E gene variant. Many patients succumb in infancy to HRD due to overwhelming infections mainly caused by Pneumococcus spp. Knowledge related to the immune system in these patients is scarce. PURPOSE: To define the immune phenotype of a cohort of HRD patients including their cellular, humoral, and neutrophil functions. METHODS: The study included HRD patients followed at Soroka University Medical Center. Clinical and immunological data were obtained, including immunoglobulin concentrations, specific antibody titers, lymphocyte subpopulations, lymphocyte proliferation, and neutrophil functions. RESULTS: Nine patients (5 females and 4 males) were enrolled, aged 6 months to 15 years. All received amoxicillin prophylaxis as part of a routine established previously. Three patients had bacteremia with Klebsiella, Shigella spp., and Candida. Three patients had confirmed coronavirus disease 19 (COVID-19), and two of them died from this infection. All patients had normal blood counts. Patients showed high total IgA and IgE levels, low anti-pneumococcal antibodies in spite of a routine vaccination schedule, and reduced frequency of naive B cells with increased frequency of CD21lowCD27- B cells. All patients had abnormal T-cell population distributions, including reduced terminally differentiated effector memory CD8, inverted CD4/CD8 ratios, and impaired phytohemagglutinin (PHA)-induced lymphocyte proliferation. Neutrophil superoxide production and chemotaxis were normal in all patients tested. CONCLUSION: HRD is a combined immunodeficiency disease with syndromic features, manifesting in severe invasive bacterial and viral infections.

Clinical features and tubulin folding cofactor E gene analysis in Iranian patients with Sanjad-Sakati syndrome / Características clínicas e análise genética e de cofatores de dobramento da tubulinaem pacientes iranianos com síndrome de Sanjad-Sakati

Abstract Objective Permanent hypoparathyroidism can be presented as part of genetic disorders such as Sanjad-Sakati syndrome (also known as hypoparathyroidism—intellectual disability-dysmorphism), which is a rare autosomal recessive disorder. Our aim was to confirm the diagnosis of a group of patients with dysmorphism, poor growth, and hypoparathyroidism clinically labeled as Sanjad-Sakati syndrome and to identify for the first time the genetic variations on Iranian patients with the same ethnic origin. Methods In this study, 29 cases from 23 unrelated Arab kindreds with permanent hypoparathyroidism and dysmorphism indicating Sanjad-Sakati syndrome were enrolled for 10 years in the southwest of Iran. The mutational analysis by direct sequencing of the tubulin folding cofactor E gene was performed for the patients and their families, as well as their fetuses using genomic DNA. Results Twenty-eight out of 29 cases had parental consanguinity. Twenty-seven cases presented with hypocalcemia seizure and two were referred because of poor weight gain and were found to have asymptomatic hypocalcemia. The dysmorphic features, hypocalcemia in the setting of low to normal parathyroid hormone levels and high phosphorus led to the diagnosis of these cases. Sequencing analysis of the tubulin folding cofactor E gene revealed a homozygous 12-bp deletion (c.155-166del) for all patients. Following that, prenatal diagnosis was performed for eight families, and two fetuses with a homozygous 12-bp deletion were identified. Conclusion These results make it much easier and faster to diagnose this syndrome from other similar dysmorphisms and also help to detect carriers, as well as prenatal diagnosis of Sanjad-Sakati syndrome in high-risk families in this population.

Resumo Objetivo O hipoparatireoidismo permanente pode estar presente como parte das doenças genéticas como na síndrome de Sanjad-Sakati (também chamada de síndrome de hipoparatireoidismo, retardo e dismorfismo), que é um distúrbio autossômico recessivo raro. Nosso objetivo foi confirmar o diagnóstico de um grupo de pacientes com dismorfismo, crescimento deficiente e hipoparatireoidismo clinicamente identificado como síndrome de Sanjad-Sakati e identificar as variações genéticas, pela primeira vez, em pacientes iranianos com a mesma origem étnica. Métodos Neste estudo, foram inscritos 29 casos de 23 famílias árabes sem parentesco com hipoparatireoidismo e dismorfismo indicando síndrome de Sanjad-Sakati, durante 10 anos no sudoeste do Irã. Foi feita a análise mutacional por sequenciamento direto do gene do cofator E de dobramento da tubulina dos pacientes e de suas famílias e também de seus fetos com o DNA genômico. Resultados Apresentaram consanguinidade parental 28 dos 29 casos. Desses, 27 casos apresentaram convulsão por hipocalcemia e dois foram encaminhados devido ao baixo ganho de peso, considerando diagnóstico de hipocalcemia assintomática. As características dismórficas, hipocalcemia na configuração de níveis de hormônio da paratireoide baixos a normais e alto nível de fósforo levaram ao diagnóstico dos casos. A análise de sequenciamento do gene do cofator E de dobramento da tubulina revelou deleção homozigótica de 12 pares de base (pb) (c.155-166del) em todos os pacientes. Após isso, foi feito o diagnóstico pré-natal em oito famílias e dois fetos foram identificados com deleção homozigótica de 12 pb. Conclusão Esses resultados tornam o diagnóstico dessa síndrome muito mais fácil e rápido do que outros dismorfismos semelhantes e também ajudam a detectar portadores, bem como o diagnóstico pré-natal da síndrome de Sanjad-Sakati em famílias de alto risco nessa população.

Clinical features and tubulin folding cofactor E gene analysis in Iranian patients with Sanjad-Sakati syndrome.

OBJECTIVE: Permanent hypoparathyroidism can be presented as part of genetic disorders such as Sanjad-Sakati syndrome (also known as hypoparathyroidism-intellectual disability-dysmorphism), which is a rare autosomal recessive disorder. Our aim was to confirm the diagnosis of a group of patients with dysmorphism, poor growth, and hypoparathyroidism clinically labeled as Sanjad-Sakati syndrome and to identify for the first time the genetic variations on Iranian patients with the same ethnic origin. METHODS: In this study, 29 cases from 23 unrelated Arab kindreds with permanent hypoparathyroidism and dysmorphism indicating Sanjad-Sakati syndrome were enrolled for 10 years in the southwest of Iran. The mutational analysis by direct sequencing of the tubulin folding cofactor E gene was performed for the patients and their families, as well as their fetuses using genomic DNA. RESULTS: Twenty-eight out of 29 cases had parental consanguinity. Twenty-seven cases presented with hypocalcemia seizure and two were referred because of poor weight gain and were found to have asymptomatic hypocalcemia. The dysmorphic features, hypocalcemia in the setting of low to normal parathyroid hormone levels and high phosphorus led to the diagnosis of these cases. Sequencing analysis of the tubulin folding cofactor E gene revealed a homozygous 12-bp deletion (c.155-166del) for all patients. Following that, prenatal diagnosis was performed for eight families, and two fetuses with a homozygous 12-bp deletion were identified. CONCLUSION: These results make it much easier and faster to diagnose this syndrome from other similar dysmorphisms and also help to detect carriers, as well as prenatal diagnosis of Sanjad-Sakati syndrome in high-risk families in this population.