Homozygous TBCE Gene Mutation c.155-166del in a Libyan Patient with Sanjad-Sakati Syndrome: Same Gene Mutation Responsible in All Arab Ethnic Patients

Sanjad-Sakati syndrome (SSS) (Online Mendelian Inheritance in Man 241410) is a rare autosomal recessive disorder also known as hypoparathyroidism-retardation-dysmorphism syndrome. It is characterized by congenital hypoparathyroidism, growth retardation, typical facial features, and variable developmental delay. SSS is caused due to mutations of the tubulin-specific chaperone E ( TBCE ) gene. In this article, we reported the first Libyan child of first parental consanguinity with SSS and whole exome sequencing results identified the homozygous missense variant c.155-166del and it encodes p.(Ser52-Gly55del) (chr1:235564867) located in the TBCE gene , chromosome 1q42.3. In addition, the patient was also diagnosed with congenital hypothyroidism and presented with acquired bilateral cataract in the first year of life. Most likely, all Arab patients with SSS syndrome have the same TBCE gene mutation.

Expanding TBCE-related phenotype-novel variant causing rigid spine, eosinophilia, neutropenia, and nocturnal hypoxemia

We report three patients with the novel variant c.100 + 1G > A of the TBCE gene and describe the presented clinical phenotype in detail. We also systematically reviewed the literature for clinical similarities and dissimilarities among all known patients with pathogenic TBCE variants. The clinical phenotype observed in patients with pathogenic TBCE variants is broader than previously described. Homozygous carriers of the c.100 + 1G > A variant exhibit a markedly milder clinical course, with no deviations in the calcium-phosphate metabolism and central nervous system pathology in MRI studies. Additionally, two patients manifest highly specific symptoms such as a rigid spine, eosinophilia, neutropenia, and nocturnal hypoxemia. Furthermore, cryptorchidism was observed in male patients. The identification of the pathogenic c.100 + 1G > A variant has thus far been limited to patients of Central-Eastern European descent, suggesting a potential founder mutation in this population.

Oral Facial Manifestations of Sanjad-Sakati Syndrome: A Literature Review

Aim: To perform a comprehensive review of orofacial manifestations of Sanjad–Sakati syndrome (SSS). Methods: A comprehensive electronic literature search was performed using PubMed, Scopus and Cochrane library databases. The search keywords included were “Sanjad–Sakati syndrome (SSS)”, “dental manifestations”, “dental management”, “oral health”, “dental care for patients with SSS”, “dental health of people with SSS”, “caries”, and “oral hygiene”. The inclusion criteria were papers published only in English, papers published by August 2021, and papers discussing orofacial manifestations of SSS and language. Results: The search of the databases retrieved eleven case reports and three case series studies. Overall, 56 cases (11 case reports and 3 case series studies) were reported on Sanjad–Sakati syndrome in the published literature. The majority of the reports are from the Middle Eastern region. Conclusions: The reported orofacial manifestations of SSS include beaked nose, depressed nasal bridge, enamel hypoplasia, hypodontia, low-set ears, posteriorly rotated ears, deep-set eyes, microcephaly, microdontia, micrognathia, prominent forehead, retrognathia, and thin lips. The review paper also establishes the importance of the dental under general anesthesia in SSS individuals.

Hypoparathyroidism-retardation-dysmorphism syndrome-Clinical insights from a large longitudinal cohort in a single medical center

BACKGROUND

Hypoparathyroidism, retardation, and dysmorphism (HRD) Syndrome is a rare disease composed of hypoparathyroidism, retardation of both growth and development, and distinctive dysmorphic features. Here, we describe the long-term morbidity and mortality in a large cohort of HRD patients and suggest recommendations for follow up and treatment.

METHODS

Medical records of 63 HRD syndrome patients who were followed at Soroka Medical Center during 1989-2019 were reviewed retrospectively. Information regarding demographics, medical complications, laboratory findings, and imaging studies was collected.

RESULTS

The mortality rate was 52%. The main causes of death were infectious diseases including pneumonia, septic shock, and meningitis. Multiple comorbidities were found including brain anomalies in 90% of examined patients (basal ganglia calcifications, tightening of corpus callosum, Chiari malformation, hydrocephalous, and brain atrophy), seizures in 62%, nephrocalcinosis and/or nephrolithiasis in 47%, multiple eye anomalies were recorded in 40%, bowel obstructions in 9.5%, and variable expression of both conductive and senso-neural hearing loss was documented in 9.5%.

CONCLUSION

HRD is a severe multisystem disease. Active surveillance is indicated to prevent and treat complications associated with this rare syndrome.

Correcting hypophosphataemia in a paediatric patient with Sanjad-Sakati syndrome through a single oral dose of potassium phosphate intravenous solution

Sanjad–Sakati syndrome is an autosomal recessive disorder that is quite common in Kuwait. Among a wide range of complications in Sanjad–Sakati syndrome patients is the vulnerability to infections and subsequent hypophosphataemia. Hypophosphataemia is a metabolic alteration that contributes to numerous consequences such as cardiac arrhythmia. Therefore, if hypophosphataemia is left unresolved, it may culminate in death. A 20-month-old boy of 2.5 kg body weight diagnosed with Sanjad–Sakati syndrome was initially admitted to the paediatric intensive care unit after recovering from COVID-19, and then shifted to the general ward. He was diagnosed with recurrent pneumonia and urinary tract infection. After 9 days, the patient showed severe hypophosphataemia with serum phosphate concentration reaching 0.33 mmol/L. Despite the availability of potassium phosphate intravenous solution, it was difficult to administer potassium phosphate intravenously because of the small body size and low body weight of the patient. Therefore, 0.6 mL potassium phosphate containing 2.4 mEq of potassium and 5.3 mEq of phosphate was administered through a nasogastric tube. The patient showed rapid response after a single dose through the nasogastric tube. Such an intervention in Sanjad–Sakati syndrome patients shows possible advantages of shifting drug administration from intravenous to oral route that includes a convenient route of administration, whether in the intensive care unit or in the general ward. Moreover, shifting drug administration from the intravenous to oral route overcomes the risk of cannula-induced infection and reduces nurses’ workload.

Overlapping phenotype comprising Kenny-Caffey type 2 and Sanjad-Sakati syndromes: The first case report

Kenny-Caffey syndrome (KCS) is a rare hereditary skeletal disorder involving hypoparathyroidism. The autosomal dominant form (KCS2), caused by heterozygous pathogenic variants in the FAM111A gene, is distinguished from the autosomal recessive form (KCS1) and Sanjad-Sakati syndrome (SSS), both caused by pathogenic variants in the tubulin folding cofactor E (TBCE) gene, by the absence of microcephaly and intellectual disability. We present a patient with KCS2 caused by a de novo pathogenic variant c.1706G>A (p.Arg569His) in FAM111A gene, presenting intellectual disability and microcephaly, which are considered to be typical signs of SSS. We suggest that KCS1, KCS2, and SSS may not represent mutually exclusive clinical entities, but possibly an overlapping spectrum.

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.

Neurological Manifestations of Sanjad–Sakati Syndrome: New Three Reported Cases from Tunisia

Sanjad–Sakati syndrome (SSS), or hypoparathyroidism–mental retardation dysmorphism syndrome, is a rare autosomal recessive congenital disorder characterized by congenital hypoparathyroidism, growth and neurodevelopmental delay, acute symptomatic seizures due to hypocalcemia, and dysmorphic features. The syndrome is underdiagnosed, and neurological manifestations are not previously described. We report three Tunisian patients with SSS revealed by acute symptomatic hypocalcemic epileptic seizures. Despite the well-controlled seizures, patients tend to continue having poor growth and neurological outcome. The diagnosis of SSS allowed for proper treatment of the patients, prevented associated comorbidities, and provided genetic counseling to their families.

Sanjad-Sakati syndrome with macrocytic anemia and failure to thrive: a case from South Jordan

Backgorund: Sanjad-Sakati syndrome (SSS) is a rare autosomal recessive disease caused by a deletion mutation (155-166del) in exon 3 of the TBCE gene on chromosome 1q42-43. The syndrome is characterized by primary hypoparathyroidism, typical dysmorphic features and severe growth retardation.

CASE PRESENTATION

We encountered a 2-year-old boy with hypocalcemia, failure to thrive and macrocytic anemia. The patient had the characteristic features of SSS and genetic testing confirmed that he was homozygous for the TBCE mutation. Although malabsorption was initially considered the cause of his symptoms, the results did not confirm that diagnosis. Our patient had cow milk protein allergy and folic acid deficiency, which has not been described in previous SSS cases. It was difficult to treat the patient's hyperphosphatemia and we ultimately selected sevelamer treatment, which was tolerated well and improved his hypocalcemia.

CONCLUSIONS

SSS should be considered in the differential diagnosis of any infant with hypocalcemia, dysmorphism and failure to thrive.

Hypoparathyroidism

Hypoparathyroidism is a disease characterized by inadequately low circulating concentrations of parathyroid hormone (PTH) resulting in low calcium levels and increased phosphate levels in the blood. Symptoms of the disease result from increased neuromuscular irritability caused by hypocalcaemia and include tingling, muscle cramps and seizures. The most common cause of the disease is inadvertent removal of, or injury to, the parathyroid glands during neck surgery, followed by genetic, idiopathic and autoimmune aetiologies. Conventional treatment includes activated vitamin D and/or calcium supplements, but this treatment does not fully replace the functions of PTH and can lead to short-term problems (such as hypocalcaemia, hypercalcaemia and increased urinary calcium excretion) and long-term complications (which include nephrocalcinosis, kidney stones and brain calcifications). PTH replacement has emerged as a new treatment option. Clinical trials using human PTH(1-34) and PTH(1-84) showed that this treatment was safe and effective in studies lasting up to 6 years. Recombinant human PTH(1-84) has been approved in the United States and Europe for the management of hypoparathyroidism; however, its effect on long-term complications is still being evaluated. Clinical practice guidelines, which describe the consensus of experts in the field, have been published and recognize the need for more research to optimize care. In this Primer, we summarize current knowledge of the prevalence, pathophysiology, clinical presentation and management of hypoparathyroidism.

Sanjad-Sakati syndrome in a Tunisian child

Sanjad-Sakati syndrome (SSS) (OMIM 241410) is a rare autosomal recessive disorder characterized by congenital hypoparathyroidism with growth and mental retardation associated with seizures and a characteristic physiognomy. SSS molecular pathology has been shown to be due to mutations in the TBCE gene on chromosome 1q42-q43. All affected patients of Arab origin are homozygous for a 12-bp (155-166del) deletion in exon 3 of this gene. We report on a Tunisian child with SSS who was homozygous for the 155-166del mutation. Our findings provide additional support of the common (155-166del) deletion founder effect in exon 3 of the TBCE gene in Arab patients. It is very likely that this mutation originated in the Middle East and was introduced in Tunisia by the Banu Hilal invaders.

[Hand and endocrine diseases]

The whole of hormones likely influence state of hands, modifying colouring and trophicity of the skin and having influence on its muscular, tendineous, osseous, articular components. Thus state of the hands contributes to the recognition of the endocrine diseases: hot and moist hands of the Graves' disease, dry, cold and infiltrated hands in myxoedema, pale and fine hands of hypopituitarism, broad and thick hand of acromegaly, brachymetacarpia in the pseudohypoparathyroidism… Diabetes exposes particularly to tendineous and articular retractions, to whitlows and ungual mycosis.