2023 ACMG Annual Clinical Genetics Meeting Digital Edition: Poster Gallery-Uniparental Disomy of Chromosome 19 in an Individual with Oculocutaneous Albinism, Neurodevelopmental Disorder, and Failure to Thrive

Uniparental Disomy of Chromosome 19 in an Individual with Oculocutaneous Albinism, Neurodevelopmental Disorder, and Failure to Thrive

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The document discusses a case study of an individual with uniparental disomy (UPD) of chromosome 19. UPD occurs when both copies of a chromosome are inherited from a single parent. This can lead to genomic imprinting defects and various syndromes or features. However, UPD may also have no effect on health and development.<br /><br />In this case, the individual was born to a mother of advanced age and experienced intrauterine growth restriction. They were born full-term via C-section and had a low birth weight. The individual was diagnosed with failure to thrive in the newborn period and later developed nystagmus, global developmental delay, ocular albinism, and autism spectrum disorder. They were also diagnosed with autoimmune hepatitis as a teenager.<br /><br />Ophthalmology examination revealed visual abnormalities such as iris transillumination defects, optic nerve hypoplasia, and nystagmus. Genetic testing using chromosome microarray identified UPD of chromosome 19, but the parent of origin is unknown. Two genes on chromosome 19, BLOC1S3 and AP3D1, were identified as potential contributors to the phenotype, but further sequencing has not been performed. The individual does not exhibit bleeding problems or other features associated with Hermansky-Pudlak syndrome, which are commonly associated with these genes.<br /><br />Further investigation through whole exome sequencing is planned to identify any other genetic causes for the individual's condition. The document also mentions that the prevalence of UPD may be higher in the general population than previously thought.<br /><br />In summary, this study presents a case of an individual with UPD of chromosome 19 and various clinical features including oculocutaneous albinism, neurodevelopmental disorder, and failure to thrive. The parent of origin for the UPD is unknown, and further genetic testing is planned to identify any other potential genetic causes.

Asset Subtitle

Presenting Author - Rebecca Procopio, MS, CGC; Co-Author - Adele S. Schneider, MD, FACMG;

Meta Tag

Chromosomal Abnormalities

Eye disorders

Genetic Testing

Imprinting

Methylation

Microarray

Phenotype

Uniparental Disomy

Co-Author Adele S. Schneider, MD, FACMG

Presenting Author Rebecca Procopio, MS, CGC

Keywords

uniparental disomy

chromosome 19

genomic imprinting defects

syndromes

intrauterine growth restriction

failure to thrive

nystagmus

ocular albinism

autism spectrum disorder

autoimmune hepatitis