One Blood Spot Twelve Disorders
Dr. Lena Jafri, Section Head, Chemical Pathology
Department of Pathology and Laboratory Medicince
Newborn screening (NBS) programs are an essential health initiative aimed at identifying genetic and metabolic disorders in newborns before symptoms appear. The primary goal of these programs is to prevent severe health complications and death by early detection and treatment of these conditions. The NBS Program was established and implemented in Jan 2019 at Aga Khan University Hospital (AKUH) main campus. We started with the screening of Congenital Hypothyroidism (CH) at
AKUH by collecting blood spots from heel prick of every baby born on dried blood spot (DBS) filter paper and sending it to the lab for analysis of neonatal thyroid stimulating hormone (nTSH). In January 2021 another disorder was added to the NBS Program which was Congenital Adrenal Hyperplasia (CAH) with the help of DBS-17 hydroxy progesterone (17OHP). Both disorders fulfill the criteria of Wilson and Jungner (W & J) and hence are part of the NBS Program. The W & J criteria serves as a guide for the selection of conditions that would be suitable for screening, based on the disease burden, screening and diagnostic capacity to detect the condition at an early stage and the availability of an acceptable treatment. A screen positive result does not mean that a baby has a disease; only that further testing is required. If a baby screens positive, the lab contacts the treating physicians and keep a follow up for screen positive babies.
In 2021 with the procurement of first LCMSMS in the institute we validated amino acids, acylcarnitines and succinylacetone on DBS of newborns (DBS-Metabolic profile). Despite the high sensitivity and specificity of MS/MS screening, the low prevalence of screened diseases leads to an increased number of false-positive results hence second tier tests are essential. To initiate NBS-Extended Panel at AKUH we plan to move in phases by introducing second tier tests gradually and following W & J criteria. On 23rd of February 2023 we have launched Selected Newborn Screening Panel for eight core and four secondary Inherited Metabolic Disorders at AKU main campus. With the help of these screening tests on LCMSMS with just one blood spot we can now screen for 12 disorders including amino acidopathies, urea cycle disorder, and organic acid disorders.
