Congenital Hypothyroidism: Facts, Facets & Therapy.

BACKGROUND: Thyroid hormone (T3) is essential for normal development of children enabling brain development and somatic growth. However, certain individuals are genetically predisposed with insufficient or no thyroid hormones. Such a condition is termed congenital hypothyroidism (CH). OBJECTIVE: In the present review, a brief back ground about congenital hypothyroidism, factors associated with CH leading to thyroid dysgenesis and thyroid dyshormonogenesis is elaborated. Additionally, the guidelines for available treatment options, management and follow-up required for patients diagnosed with CH are discussed. Treatment options in terms of treatment initiation and dosage of hormone replacement are discussed. CONCLUSION: Though CH is considered as the most common neonatal metabolic disorder, it is also easily treatable compared to other metabolic or hereditary diseases. The outcome of CH treatment depends on the compliance of parents early in life and by patients themselves during later part of life.

Evolution of Synonymous Codon Usage in the Mitogenomes of Certain Species of Bilaterian Lineage with Special Reference to Chaetognatha.

Chaetognatha is a minor phylum, comprising transparent marine invertebrates varying in size from 0.5 to 12 cm. The exact phylogenetic position of Chaetognatha in Metazoa has not been deciphered as some embryological characteristics place chaetognaths among deuterostomes and some morphological characteristics place these among protostomes. In this study, the major factors that drive synonymous codon usage bias (SCUB) in the mitogenomes of representative species of Chaetognatha and chosen species of other closely related phyla were analyzed. Spearman's rank correlation analyses of nucleotide contents suggested that mutational pressure and selection were acting in all examined mitogenomes but with varying intensities. The quantification of SCUB using effective number of codons vs. GC composition at the third codon position (GC3) plot suggested that mutational pressure due to GC compositional constraints might be one of the major influencing forces driving the SCUB in all chaetognaths except Sagitta enflata. However, neutrality plots revealed no significant correlation between GC3 and cumulative GC content at first and second codon positions (GC12) in all other species, except in Daphnia pulex. The parity rule 2 bias plot showed that significant compositional differences existed between C and G, as well as between A and T, contents in most of the protein-coding genes (PCGs) and, comparatively, A and T contents were used more proportionally than C and G contents in all chosen mitogenomes. Chi-square analysis revealed the presence of putative optimal codons in all species, except in S. enflata. The correspondence analysis identified that mutational pressure and selection act on the mitogenomes of the selected chaetognaths and other phyla with varying intensities. The cluster analysis based on relative synonymous codon usage (RSCU) values revealed that RSCU variations in the PCGs of mitogenomes of chaetognaths are more comparable with those of protostomes. Apart from mutational pressure and selection, certain unknown selective forces might be acting on the PCGs in the analyzed mitogenomes as the phenomenon of SCUB could not be explained by mutational pressure, by selection, or by both.