Genetic testing uncover hidden causes of rare chromosomal disorders

Rare genetic disorders affect more than 300 million people worldwide, with children making up 70% of those impacted, according to EURORDIS. These conditions often go undiagnosed for years due to complex, varied symptoms. Today, genetic testing offers powerful insights into DNA, enabling accurate diagnoses, targeted care, and vital support.

Each June, Rare Chromosome Disorder Awareness Day casts a necessary spotlight on these silent battles. With every confirmed diagnosis, more families are finally gaining clarity, community, and hope, which are essential steps toward navigating life with rare genetic conditions.

Timely diagnosis, better outcome

Seventeen-year-old Lucas, a cheerful and affectionate boy from Singapore, lives with Angelman syndrome (AS), a rare neurogenetic condition that affects roughly 1 in every 15,000 live births.

His bright smile and infectious laughter are common signs of AS. But behind them are daily struggles with movement, communication, and learning.

Lucas’ condition first emerged at just two months old. Following a high fever from a urinary tract infection, he began having unexplained seizures. His mother, Mrs. Oon, remembers the fear vividly: “He was trembling. It was terrifying.” Despite treatment, the seizures continued. Realizing something more serious was at play, his doctors moved quickly to order comprehensive genetic testing.

The test results confirmed that Lucas had Angelman syndrome. While children with AS typically face significant delays in speech and coordination, early detection enabled Lucas to begin timely intervention.

Through a structured support plan, Lucas learned to walk with the help of a pacer walker and communicate using visual text cards. These tools have allowed him to engage with the world around him, enjoy outdoor activities, and build meaningful connections.

Stop the Mutation Cycle

For years, Chu’ family in Vietnam lived without answers as their two sons, Chu Nam Phong and Chu Nam Khánh, struggled with severe muscle weakness from infancy. Multiple hospital visits yielded no diagnosis. Frustration turned to despair as they watched their boys grow without understanding the cause of their condition.

The doctor suggested Whole Exome Sequencing (WES) provided by BGI Genomics for a genetic profiling of the problem. This cutting-edge genetic test revealed a mutation in the CHKB gene, confirming that the children had Megaconial Muscular Dystrophy, an extremely rare and progressively debilitating disease.

“We were desperate and frustrated,” the mother shared. “But genetic testing gave us answers. It gave us a direction, and a way to help our children.”

Her advice to other families facing similar mysteries is clear: don’t wait. Genetic testing is more than a diagnosis, it’s a lifeline. It helps begin the right treatment, supports better care planning, and, in some cases, guides future family decisions.

Complexity of chromosome disorders

Dr. Mikhail Fediakov, a leading geneticist and Head of the Genetics Department at Genscreen, Uzbekistan—a joint venture with BGI Genomics, explained that rare chromosome disorders are classified as congenital disorders. They often result from a complex interplay of genetic mutations and environmental influences. Remarkably, up to 50% of congenital anomalies still have no identifiable cause.

“Some conditions are caused by chromosomal abnormalities or single-gene mutations.  Some others are linked to external factors such as maternal infections, poor nutrition, or exposure to harmful substances during pregnancy,” explained Dr. Mikhail Fediakov. He emphasized that these factors often overlap, which makes diagnosis and prevention especially difficult.

In Central Asia, congenital disorders mirror global trends but are distinctly influenced by regional circumstances. Factors such as consanguineous marriages, environmental exposures, and limited access to quality prenatal care contribute to the prevalence of congenital conditions. Consequently, congenital heart defects, neural tube anomalies, congenital hypothyroidism, cleft lip and palate, Down syndrome, and inherited genetic diseases are reported across the region.

Chromosome Awareness Day is a reminder that even in the face of uncertainty, hope shines through. With the power of genetic testing, families like Lucas’ and the Chus’ are turning confusion into clarity. Every diagnosis is the beginning of a stronger, more supported journey.

About Clinical Whole Exome Sequencing (cWES)

XOME™ Clinical Whole Exome Sequencing (cWES) examines the DNA sequence of over 180,000 exons across 22,000 genes, screening for more than 4,000 monogenic diseases. Search for genes of interest and associated mutations, and confirm whether the Xome test is suitable for your requirements.

About BGI Genomics

BGI Genomics, headquartered in Shenzhen, China, is the world's leading integrated solutions provider of precision medicine. Our services cover more than 100 countries and regions, involving more than 2,300 medical institutions. In July 2017, as a subsidiary of BGI Group, BGI Genomics (300676.SZ) was officially listed on the Shenzhen Stock Exchange.