This journal only 2018, Number 1 Rev Mex Pediatr 2018; 85 (1) Update on congenital hypothyroidism: etiology, clinical presentation, diagnosis and treatment. Part two Rivera-Hernández A, Huerta-Martínez H, Centeno-Navarrete Y, Zurita-Cruz JN Full text How to cite this article Language: Spanish References: 41 Page: 34-40 PDF size: 250.23 Kb. Key words: Congenital hypothyroidism, diagnosis, treatment, review. ABSTRACT In this second part will be addressed aspects of congenital hypothyroidism (CH) on the etiology, clinical feature, diagnosis, treatment and follow-up. CH is classified, by its genetic base, in sporadic and hereditary. The most common cause of sporadic HC is thyroid dysgenesis and in the case of hereditary HC, dishormonogenesis due to mutations in genes that code for proteins involved in the synthesis of thyroid hormones (TH). The uncommon causes of hereditary CH are the resistance syndromes, with alterations in cell membrane transporters, receptors and metabolism of TH. In Mexico the diagnosis of CH has two stages, the first through the neonatal screening with TSH (95% of the newborns are asymptomatic), and if this is positive (› 10 µU/mL), in the second stage the thyroid profile is performed to confirm or rule out the diagnosis. However, other studies such as serum thyroglobulin, thyroid scintigraphy and ultrasound imaging allow us to clarify the etiology; nevertheless, these studies are not essential to start treatment, which must be started within the first two weeks of life, to avoid neurological sequelae. In general, treatment with levothyroxine is for life; but at three years of age, it is convenient to reassess the HC diagnosis, since up to 35% of cases are transient. The follow-up is multidisciplinary and should include pediatricians, endocrinologists and experts in Rehabilitation Medicine. REFERENCES Seo MK, Yoon JS, So CH, Lee HS, Hwang JS. Intellectual development in preschool children with early treated congenital hypothyroidism. Ann Pediatr Endocrinol Metab. 2017; 22(2): 102- 107. Trumpff C, De Shepper JD, Vanderfaeillie J, Vercruysse, Van Oyen H, Moreno-Reyes R et al. Neonatal thyroid-stimulating hormone concentration and psychomotor development at preschool age. Arch Dis Child. 2016; 101(12): 1100-1106. Castanet M, Polak M. Spectrum of human Foxe1/TTF2 mutations. Horm Res Paediatr. 2010; 73(6): 423-429. Yousefichaijan P, Dorreh F, Rafeie M, Sharafkhah M, Safi F, Amiri M et al. Congenital anomalies of kidney and upper urinary tract in children with congenital hypothyroidism; a case-control study. J Renal Inj Prev. 2015; 4(4): 120-126. Yousefi CP, Dorreh F, Sharafkhanh M, Amiri M, Ebrahimemonfared M, Rafeie M et al. Congenital urogenital abnormalities in children with congenital hypothyroidism. Med J Islam Repub Iran. 2017; 31: 7. Park SM, Chatterjee VK. Genetics of congenital hypothyroidism. J Med Genet. 2005; 42(5): 379-389. Vono-Toniolo J, Kopp P. Thyroglobulin gene mutations and other genetic defects associated with congenital hypothyroidism. Arq Bras Endocrinol Metabol. 2004; 48(1): 70-82. Narumi S, Hasegawa T. TSH resistance revisited. Endocr J. 2015; 62(5): 393-398. Levine MA. An update on the clinical and molecular characteristics of pseudohypoparathyroidism. Curr Opin Endocrinol Diabetes Obes. 2012; 19(6): 443-451. Chow YP, Abdul Murad NA, Mohd Rani Z, Khoo JS, Chong PS, Wu LL et al. Exome sequencing identifies SLC26A4, GJB2, SCARB2 and DUOX2 mutations in 2 siblings with Pendred syndrome in a Malaysian family. Orphanet J Rare Dis. 2017; 12(1): 40. Armour CM, Kersseboom S, Yoon G, Visser TJ. Further insights into the Allan- Herndon-Dudley syndrome: clinical and functional characterization of a novel MCT8 mutation. PLoS One. 2015; 10(10): e0139343. Mamanasiri S, Yesil S, Dumitrescu AM, Liao XH, Demir T, Weiss RE, Refetoff S. Mosaicism of a thyroid hormone receptor beta gene mutation in resistance to thyroid hormone. J Clin Endocrinol Metab. 2006; 91: 3471-3477. Bochukova E, Schoenmakers N, Agostini M, Schoenmakers E, Rajanayagam O, Keogh JM et al. A mutation in the thyroid hormone receptor alpha gene. N Engl J Med. 2012; 366(3): 243-249. Onigata K, Szinnai G. Resistance to thyroid hormone. Endocr Dev. 2014; 26: 118-129. Dumitrescu AM, Di Cosmo C, Liao XH, Weiss RE, Refetoff S. The syndrome of inherited partial SBP2 deficiency in humans. Antioxid Redox Signal. 2010; 12(7): 905-920. Tajima T, Nakamura A, Morikawa S, Ishizu K. Neonatal screening and a new cause of congenital central hypothyroidism. Ann Pediatr Endocrinol Metab. 2014; 19(3): 117-121. De Graaff LC, Argente J, Veenma DC, Drent ML, Uitterlinden AG, Hokken-Koelega HA. PROP 1, HESX1, POU1F1, LHX3 and LHX4 mutation and deletion screening and GH1 P89L and IVS3 +1/+2 mutation screening in a Dutch nationwide cohort of patients with combined pituitary hormone deficiency. Horm Res Paediatr. 2010; 73(5): 363-371. Cameo T, Gumer LB, Williams KM, Gomez J, McMahon DJ Oberfield SE. A retrospective review of newborn screening for congenital hypothyroidism and newborn thyroid disease at a major medical center. Clin Pediatr (Phila). 2013; 52(11): 1054-1058. Unüvar T, Demir K, Abacı A, Büyükgebiz A, Böber E. The role of initial clinical and laboratory findings in infants with hyperthyrotropinemia to predict transient or permanent hypothyroidism. J Clin Res Pediatr Endocrinol. 2013; 5(3): 170-173. Rabbiosi S, Vigone MC, Cortinovis F, Zamproni I, Fugazzola L, Persani L et al. Congenital hypothyroidism with eutopic thyroid gland: analysis of clinical and biochemical features at diagnosis and after re-evaluation. J Clin Endocrinol Metab. 2013; 98(4): 1395-1402. Moleti M, Sturniolo G, Trimarchi F, Vermiglio F. The changing phenotype of iodine deficiency disorders: a review of thirty-five years of research in north-eastern Sicily. Ann Ist Super Sanita. 2016; 52(4): 550-557. Ford GA, Denniston S, Sesser D, Skeels MR, LaFranchi SH. Transient versus permanent congenital hypothyroidism after the 3 years in infants detected on the first versus second newborn screening test in Oregon, USA. Horm Res Paediatr. 2016; 86(3): 169-177. Kim MR, Park HW, Chung S. A baby with congenital hypothyroidism born to a hypothyroid mother who expressed undiagnosed thyroid stimulation blocking antibody. Ann Pediatr Endocrinol Metab. 2016; 21(3): 161-163. Connelly KJ, Boston BA, Pearce EN, Sesser D, Snyder D, Baverrman LE et al. Congenital hypothyroidism caused by excess prenatal maternal iodine ingestion. J Pediatr. 2012; 16(4): 760-762. Korzeniewki SJ, Grigorescu V, Kleyn M, Young W, Birbeck G, Todem D et al. Transient hypothyroidism at 3-year follow-up among cases of congenital hypothyroidism detected by newborn screening. J Pediatr. 2013; 162(1): 177-182. Park IS, Yoon JS, So CH, Lee HS HJ. Predictors of transient congenital hypothyroidism in children with eutopic thyroid gland. Ann Pediatr Endocrinol Metab. 2017; 22(2): 115-158. Foley TP Jr. Hypothyroidism. Pediatr Rev. 2004; 25(3): 94-100. Wassner AJ. Pediatric hypothyroidism: diagnosis and treatment. Paediatr Drugs. 2017; 19(4): 291-301. Cherella CE, Wassner AJ. Congenital hypothyroidism: insights into pathogenesis and treatment intern. Int J Pediatr Endocrinol. 2017; 2017: 11. Soneda A, Adachi M, Murpya K, Asakura Y, Yamagami Y, Hirahara F. Overall usefulness of newborn screening for congenital hypothyroidism by using free thyroxine measurement. Endocr J. 2014; 61(10): 1025-1030. Hallett A, Evans C, Moat S, Barton J, Warner J, Gregory JW. Hypothyroidism in preterm infants following normal screening. Ann Clin Biochem. 2011; 48(Pt 6): 572-574. Adachi M, Soneda A, Asakura Y, Muroya K, Yamagami Y, Hirahara F. Mass screening of newborns for congenital hypothyroidism of central origin by free thyroxine measurement of blood samples on filter paper. Eur J Endocrinol. 2012; 166(5): 829-838. Fujiwara F, Fujikura K, Okuhara K, Tsubaki J, Fukushi M, Fujita K et al. Central congenital hypothyroidism detected by neonatal screening in Sapporo, Japan (2000-2004): it’s prevalence and clinical characteristics. Clin Pediatr Endocrinol. 2008; 17(3): 65-69. Rastogi MV, LaFranchi SH. Congenital hypothyroidism. Orphanet J Rare Dis. 2010; 5: 17. Keller-Petrot I, Leger J, Sergent-Alaoui A, de Labriolle-Vaylet C. Congenital hypothyroidism: role of nuclear medicine. Semin Nucl Med. 2017; 47(2): 135-142. Borges MF, Sedassari NA, Sedassari AA, Marquez FL, Ferreira BP, Lara BH et al. Timing of thyroid ultrasonography in the etiological investigation of congenital hypothyroidism. Arch Endocrinol Metab. 2017; 61(5): 432-437. Schoen EJ, Clapp W, To TT, Fireman BH. The key role of new thyroid scintigraphy with isotopic iodide (123I) in defining and managing congenital hypothyroidism. Pediatrics. 2004; 114(6): e683-e688. Kang MJ, Chung HR, Oh YJ, Shim YS, Yang S, Hwang IT. Threeyear follow-up of children with abnormal newborn screening results for congenital hypothyroidism. Pediatr Neonatol. 2017; 58(5): 442-448. Dew R, Okosieme O, Dayan C, Eligar V, Khan I, Razvi S et al. Clinical, behavioural and pharmacogenomic factors influencing the response to levothyroxine therapy in patients with primary hypothyroidismprotocol for a systematic review. Syst Rev. 2017; 6: 60. Rahmani K, Yarahmadi S, Etemad K, Koosha A, Mehrabi Y, Aghang N SH. Congenital hypothyroidism: optimal initial dosage and time of initiation of treatment: a systematic review. Int J Endocrinol Metab. 2016; 14(3): e36080. American Academy of Pediatrics, Rose SR; Section on Endocrinology and Committee on Genetics, American Thyroid Association, Brown RS; Public Health Committee, Lawson Wilkins Pediatric Endocrine Society, Foley T, Kaplowitz PB, Kaye CI, Sundararajan S, Varma SK. Update of newborn screening and therapy for congenital hypothyroidism. Pediatrics. 2006; 117(6): 2290-2303.