A brief summary of human molecular genetic techniques for clinical psychiatrists

Concerted and systematic efforts to understand genetics of human health and disease over the preceding 60 odd years have witnessed remarkable progress. The incremental gains through this journey were enabled by chromosomal analysis, recombinant deoxyribonucleic acid (DNA) techniques, notable discovery of single nucleotide polymorphisms following the Human Genome Project, consequent genome-wide variant-based studies, and now whole genome sequencing with ultimate diagnostic potential. Of note, success in prediction and prevention of chromosomal and single gene disorders comprising ~six to eight per cent each of all genetic disorders have been unprecedented but uncovering genetics of common complex disorders conferring ~60% of the genetic disease burden continues to pose a challenge and await new analytical paradigms - a mix of reductionist and organismal biology together with artificial intelligence and machine learning approaches being the current trend. A brief account of this path of progress in medical genetics and genomic insights along with limitations, to achieve the overarching goals of predictive, preventive, personalised, and participatory medicine is presented in this article.

Newborn Screening and Diagnosis of Infants with Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is an autosomal recessive endocrine disorder which can manifest after birth with ambiguousgenitalia and salt-wasting crisis. However, genital ambiguity is not seen in male babies and may be mild in female babies, leading to amissed diagnosis of classical CAH at birth. In this review, we provide a standard operating protocol for routine newborn screening forCAH in Indian settings. A standardization of first tier screening tests with a single consistent set of cut-off values stratified by gestationalage is also suggested. The protocol also recommends a two-tier protocol of initial immunoassay/time resolved fluoroimmunoassayfollowed by liquid chromatography tandem mass spectrometry for confirmation of screen positive babies, wherever feasible. Routinemolecular and genetic testing is not essential for establishing the diagnosis in all screen positive babies, but has significant utility inprenatal diagnosis and genetic counseling for future pregnancy.

Association Between Neonatal Thyroid Stimulating Hormone Status and Maternal Urinary Iodine Status

Background: Maternal urinary iodine concentration (MUIC) andpercentage of neonates with Thyroid stimulating hormone (TSH)>5 mIU/L are amongst the parameters suggested for assessingadequate iodine status.Objective: To assess the correlation between MUIC andneonatal TSH levels.Study design: Cross-sectional.Settings: Tertiary care center in Delhi, India, between November2015 to November 2016.Participants: Postnatal mother-neonate dyads.Methods: TSH levels assessed among neonatal samples werestratified as below and above 5 mIU/L. MUIC was measured in544 mothers, 400 mother-neonate dyads with neonatal TSHlevels >5 mIU/L (cases) and 144 mother-neonate newbornmother dyads with neonatal TSH <5 mIU/L (controls).Results: The percentage of mothers with iodine insufficiency(9.8% vs 5.6%) as well as iodine excess (54.3% vs 41.7%) weresignificant higher in cases than controls. Mean TSH was alsohigher (P=0.0002) in both the iodine deficient and iodine excessgroup. There was no correlation between neonatal TSH valuesand MUIC.Conclusions: Lack of correlation between neonatal TSH andMUIC is due to iodine excess together with iodine deficiency.