Spinal Muscular Atrophy Type I With False Negative in Newborn Screening: A Case Report.

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by the deletion or mutation of the survival motor neuron 1 (SMN1) gene. The establishment of effective newborn screening (NBS) for SMA is important for early diagnosis so that treatment can be administered in the pre-symptomatic or early disease stages. Polymerase chain reaction (PCR)-based genetic testing with dried blood spots has been used in NBS to detect the homozygous deletion of exon 7 in SMN1, however, this methodology is not able to detect newborn infants with heterozygous deletions and/or point mutations in SMN1. We report the case of a male infant who was diagnosed with SMA despite the NBS being negative for all conditions including SMA. The patient presented with severe hypotonia and muscle weakness from around 14 days of age. SMA was suspected and sequence analysis of SMN1 and SMN2 was conducted using the multiplex ligation-dependent probe amplification (MLPA) method, which revealed compound heterozygous mutations of SMN1. The patient was diagnosed with SMA and started on modulating agents including gene therapy. His motor function improved slightly with treatment, however, his motor development remained prominently retarded by 5 months of age. This case highlights the importance of investigating SMA as a potential diagnosis even when the NBS result is negative.

Anomalous origin of the right coronary artery: First familial cases in Asia.

Congenital coronary artery abnormalities may cause sudden death, particularly in athletes. Two siblings, aged 10 and 9 years, respectively, were diagnosed with anomalous origin of the right coronary artery on multi-detector computed tomography (MDCT). The right coronary artery arose from the left coronary cusp, and was wedged between the aorta and pulmonary artery. This was also noted on cardiac ultrasonography (UCG), but in general this might not be seen on electrocardiography at rest. Although the surgical indications are unclear in the case of unproven ischemia, early recognition of the condition may reduce risk of the cardiac events during exercise. The majority of proximal coronary artery anomalies can be screened for on UCG, and confirmed on MDCT, which yields more precise clinical details and is less invasive than angiography. This is the first report of familial cases of anomalous origin of the right coronary artery in Asia.