Demographic and Clinical Aspects of Congenital Hypothyroidism (Dyshormonogenesis) in Sudan

Abstract

Introduction: Congenital hypothyroidism is the most common congenital endocrine disorder worldwide. Approximately 80 to 85% of cases are caused by defects in thyroid development (dysgenesis), the remaining 15 to 20% are due to errors of thyroid hormone biosynthesis (dyshormonogenesis). Congenital hypothyroidism is also the most common preventable cause of mental retardation. Its neurological defects can only be reversible if diagnosed and treated early. Its incidence rate is 1 out of 3000/4000 live births worldwide However, this incidence rate is higher in developing countries such as Sudan (1 of 1400/2200 newborn infants) in which its population is characterized by consanguinity (25-70%). The present study aimed to assess the demographic and clinical pattern of congenital hypothyroidism (dyshormonogenesis) in Sudan.

Material and Methods: A total of 54 patients referred to Gaffar Ibn Auf Children Hospital presented with clinical features suggesting congenital hypothyroidism (dyshormonogenesis) were enrolled in this study. Demographic and clinical data was obtained by a predesigned questionnare. Data were analyzed using SPSS 13 software. Descriptive statistics (frequencies and percentages) were obtained for categorical variables.

Results: Most patients enrolled in this study (85.7%) are descendants of consanguineous marriages. There were 11 reported families, comprising 74.3% of cases, with more than one affected member, of those family members, 68.6 % were in fact siblings. Patients from consanguineous marriage had a 96.6% positive family history. The majority of patients (97.1%) developed complications. According to the tribal origin, the vast majority of patients (65.7%) were from Afro-Asiatic tribes, whereas 34.3% were from Nilo-Saharan tribes. There was a large variation in the geographical distribution of patients. Biochemical analysis and ultrasound findings were concordant with the clinical presentation of patients.

Conclusion: 1) Early diagnosis and treatment are crucial to prevent both cognitive and motor detrimental effects of the disease. 2) Consanguineous marriages are a major risk factor in patients with congenital hypothyroidism. 3)There is a wide range of tribal variation of both Afro-Asian (65.7%) and Nilo-Saharan (34.3%) tribes. 4) Poor education and unawareness of the disease were major factors in late diagnosis, treatment and further complications.

Keywords: Congenital Hypothyroidism, Dyshormonogenesis, Sudan.