Hypercalcemia as a rare presentation of hyaline fibromatosis syndrome from different Sudanese families: two case reports.

BACKGROUND: Hyaline fibromatosis syndrome is a rare progressive autosomal recessive connective tissue disorder caused by a mutation in the ANTXR2/CMG2 gene. According to its severity, patients may present with skin nodules or visceral infiltration, which carries a poor prognosis. Hypercalcemia has not been reported as a presenting feature of this syndrome. Stimulation of osteoclasts by inflammatory factors and immobilization--induced hypercalcemia have played role in the pathophysiology. To our knowledge, this is the first report of hypercalcemia-associated hyaline fibromatosis syndrome. CASE PRESENTATION: Here, we describe cases of two Sudanese patients, a boy aged 9 months and a girl aged 3.5 years with hypercalcemia as an associated presenting feature of hyaline fibromatosis syndrome. Other features include gingival hypertrophy, painful joint swellings, and restriction of movement, which was misdiagnosed as juvenile rheumatoid arthritis. Workup showed normal phosphate, normal to mildly elevated parathyroid hormone, low vitamin D 25. Genetic testing confirmed the mutation of the ANTXR2/CMG2 gene. Both patients responded well to medical therapy for hypercalcemia, but one of them with the severe form of juvenile hyaline fibromatosis died due to sepsis, while the other one has maintained normocalcemic status. CONCLUSIONS: These cases highlight the rare presentation of this syndrome and reflect the importance of biopsy and genetic testing in reaching the diagnosis, especially when the clinical presentation can mimic other inflammatory bone disorders. Calcium levels should be checked in such cases.

A Novel Splice-Site Deletion in the POU1F1 Gene Causes Combined Pituitary Hormone Deficiency in Multiple Sudanese Pedigrees.

Pathogenic variants within the gene encoding the pituitary-specific transcription factor, POU class 1 homeobox 1 (POU1F1), are associated with combined pituitary hormone deficiency (CPHD), including growth hormone, prolactin, and thyrotropin stimulating hormone deficiencies. The aim of the study was to identify genetic aetiology in 10 subjects with CPHD from four consanguineous Sudanese families. Medical history, as well as hormonal and radiological information, was obtained from participants' medical records. Targeted genetic analysis of the POU1F1 gene was performed in two pedigrees with a typical combination of pituitary deficiencies, using Sanger sequencing, and whole-exome sequencing was performed in the other two pedigrees, where hypocortisolism and additional neurologic phenotypes were also initially diagnosed. In POU1F1 gene (NM_001122757.2) a novel homozygous splice-site deletion-namely, c.744-5_749del-was identified in all 10 tested affected family members as a cause of CPHD. Apart from typical pituitary hormonal deficiencies, most patients had delayed but spontaneous puberty; however, one female had precocious puberty. Severe post-meningitis neurologic impairment was observed in three patients, of whom two siblings had Dyke-Davidoff-Masson syndrome, and an additional distantly related patient suffered from cerebral infarction. Our report adds to the previously reported POU1F1 gene variants causing CPHD and emphasises the importance of genetic testing in countries with high rates of consanguineous marriage such as Sudan. Genetic diagnostics elucidated that the aetiologies of hypopituitarism and brain abnormalities, identified in a subset of affected members, were separate. Additionally, as central hypocortisolism is not characteristic of POU1F1 deficiency, hydrocortisone replacement therapy could be discontinued. Elucidation of a genetic cause, therefore, contributed to the more rational clinical management of hypopituitarism in affected family members.

Clinical profile, etiology, and diagnostic challenges of primary adrenal insufficiency in Sudanese children: 14-years' experience from a resource limited setting.

OBJECTIVES: Primary adrenal insufficiency (PAI) in children is an uncommon condition. Congenital adrenal hyperplasia (CAH) is the commonest cause followed by autoimmune disorders. Diagnosis and management are challenging especially in resource-limited settings. Studies from Africa are scanty and here we describe for the first time the clinical presentation, possible etiologies, and challenges in diagnosis and management of PAI in a large cohort of Sudanese children. METHODS: This was a descriptive hospital-based study where all patients diagnosed with PAI between 2006 and 2020 were reviewed. The diagnosis was based on clinical presentation, low morning cortisol ± high adrenocorticotropic hormone (ACTH), or inadequate response of cortisol to synacthen stimulation. Challenges faced in diagnosis and management were identified. RESULTS: From 422 PAI suspected patients, 309 (73.2%) had CAH, and 33 (7.8%) had PAI-like symptoms and were not furtherly discussed. Eighty patients (19%) had fulfilled the study criteria: 29 had Allgrove syndrome, nine auto-immune polyendocrinopathy syndrome, seven adrenoleukodystrophy, and one had an adrenal hemorrhage. Hyperpigmentation was the cardinal feature in 75 (93.8%) while the adrenal crisis was not uncommon. Lack of diagnostic facilities has obscured the etiology in 34 (42.5%) patients. CONCLUSIONS: PAI is not uncommon in Sudanese children where genetic causes outweigh the autoimmune ones. Many cases were missed due to nonspecific presentation, lack of awareness, and difficult access to tertiary health care facilities. In addition to the clinical findings, early morning cortisol ± ACTH levels can be used in diagnosis where facilities are limited particularly synacthen stimulation test.

Aetiologies and clinical patterns of hypopituitarism in Sudanese children.

There is paucity of reported information regarding aetiology and clinical profile of hypopituitarism from resource-limited countries particularly in populations with high rates of consanguineous marriages. Here, we are reporting the first data on this aspect from Sudan. This is a descriptive, retrospective, hospital-based study, carried out in the two main paediatric endocrinology centres in Sudan (Gafaar Ibn Auf Paediatric Tertiary Hospital and Soba University Hospital, Khartoum) from January 2006 up to December 2014. Patients' records were reviewed for relevant demographical, clinical, hormonal and radiological data using pretested study forms. The study included 156 patients. One hundred and one patients were males (M: F = 1.8:1). The commonest age groups were adolescents (57.7%). Consanguinity was found in 77.8% of patients overall and 91% of patients with congenital aetiologies. The commonest clinical presentation was short stature (93.5%). Congenital causes (86.5%) were more prevalent than acquired causes (13.5%). There were six family clusters with multiple pituitary hormone deficiencies (MPHD) and three families with isolated growth hormone (GH) deficiency (IGHD). Most of the congenital cases with MPHD were phenotypic for PROP1 gene mutation (77.5% of sporadic cases and 50% of familial cases). Craniopharyngioma was the commonest of the acquired causes (10.2%). GH was the most frequent hormone deficient (89.7%). Abnormal Magnetic resonance imaging brain findings were significantly seen more in MPHD in comparison to IGHD. The genetic forms of hypopituitarism in populations with high rates of consanguineous marriage like Sudan may be higher than those reported internationally. Molecular genetic studies are, therefore, highly recommended.

Fanconi Bickel syndrome: clinical phenotypes and genetics in a cohort of Sudanese children.

BACKGROUND: Fanconi-Bickel syndrome (FBS) is a rare condition of carbohydrate metabolism, caused by a recessive defect in the facilitative glucose transporter GLUT2 encoded by the SLC2A2 gene and characterized by a wide spectrum of phenotypical features. There is a paucity of reported data on FBS from Sub-Saharan Africa. Here, we describe the clinical, biochemical and genetic characteristics of our patients with FBS from Sudan, a country with a high consanguinity rate. PATIENTS & METHODS: Eleven patients from ten unrelated Sudanese families were included. Clinical & biochemical data were documented and imaging studies done including bone survey and abdominal ultrasound. Liver biopsy was done to confirm the pathological diagnosis in 45% of cases and molecular genetics was performed through contribution with the Exeter genomics laboratory for ten patients. RESULTS: Reported consanguinity was 70% among our patients. Growth was significantly impaired at presentation with mean weights of (-5.3 ± 1.8) SD and heights (-5.4 ± 2.5) SD. Severe chest deformity was present in (27%) and all patients showed features of rickets at presentation. Three patients had neonatal diabetes requiring insulin therapy of which one has been reported before. Six families lost undiagnosed siblings with similar clinical presentations. We identified a total of four homozygous pathogenic SLC2A2 variants in our patients, one of whom had a novel mutation. CONCLUSIONS: FBS is not uncommon in Sudan where there is a high rate of consanguinity. Many cases are likely missed because of variable presentation and lack of public and professionals' awareness. This is the first series to describe this condition from Sub-Saharan Africa.