title: The early detection of Salla disease through second-tier tests in newborn screening: how to face incidental findings.
abstract: We describe here a 34 months child, practically asymptomatic which presented with high levels of free sialic acid in urine by biochemical detection in second-tier tests newborn screening and with two disease causing mutations in SLC17A5 gene. SLC17A5 mutation analysis showed p.Tyr306* previously described and the novel mutation p.Leu167Pro. This early onset diagnosis allowed us to perform a fast and accurate genetic counseling to the family, helped to better understanding the natural history of this rare disease and probably it could promote cost reduction in future diagnostic tests in the hypothetic case of starting symptoms without diagnosis established. Moreover, an early diagnosis could save family from a long period of time until achieving a definitive diagnostic and to develop an early symptomatic and supportive management of patient to attenuate, as much as possible, disease complications. But, above all, this case illustrates the huge ethical dilemma which arises from any secondary finding (second tier) in newborn screening.
authors.affiliation: Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Santiago de Compostela, Spain; CIBER de Enfermedades Raras (CIBERER), Barcelona, Spain; IDIS, Santiago de Compostela, Spain. Electronic address: maria.luz.couce.pico@sergas.es.
authors.forename: María L
authors.initials: ML
authors.lastname: Couce
authors.affiliation: CIBER de Enfermedades Raras (CIBERER), Barcelona, Spain; Secció d'Errors Congènits del Metabolisme (IBC), Servei de Bioquímica i Genètica Molecular, Hospital Clínic, Barcelona, Spain; IDIBAPS, Barcelona, Spain.
authors.forename: Judit
authors.initials: J
authors.lastname: Macías-Vidal
authors.affiliation: Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Santiago de Compostela, Spain; IDIS, Santiago de Compostela, Spain.
authors.forename: Daisy E
authors.initials: DE
authors.lastname: Castiñeiras
authors.affiliation: Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Santiago de Compostela, Spain; IDIS, Santiago de Compostela, Spain.
authors.forename: María D
authors.initials: MD
authors.lastname: Bóveda
authors.affiliation: Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Santiago de Compostela, Spain; CIBER de Enfermedades Raras (CIBERER), Barcelona, Spain; IDIS, Santiago de Compostela, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Fraga
authors.affiliation: Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clinico Universitario de Santiago, Santiago de Compostela, Spain; IDIS, Santiago de Compostela, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Fernández-Marmiesse
authors.affiliation: CIBER de Enfermedades Raras (CIBERER), Barcelona, Spain; Secció d'Errors Congènits del Metabolisme (IBC), Servei de Bioquímica i Genètica Molecular, Hospital Clínic, Barcelona, Spain; IDIBAPS, Barcelona, Spain.
authors.forename: María J
authors.initials: MJ
authors.lastname: Coll
mesh_terms: D000595:Amino Acid Sequence; D004252:DNA Mutational Analysis; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D033162:Incidental Findings; D007223:Infant; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D009154:Mutation; D019158:N-Acetylneuraminic Acid / Q000097:blood / Q000652:urine; D015997:Neonatal Screening; D027361:Organic Anion Transporters / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D029461:Sialic Acid Storage Disease / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D027981:Symporters / Q000737:chemistry / Q000235:genetics
chemical_list: D027361:Organic Anion Transporters; D027981:Symporters; C421224:sialic acid transport proteins; D019158:N-Acetylneuraminic Acid
keywords: Free sialic acid; Lysosomal storage disorder; Neurodegenerative disorders; Newborn screening; SLC17A5 gene