Decoding the Mystery of Autosomal Recessive Chorioretinopathy-Microcephaly Syndrome

Expert Reviewed By: ⁠Dr. Brandon Colby MD

Autosomal recessive chorioretinopathy-microcephaly syndrome (ARCM) is a rare neuro-ophthalmological disease that affects both the nervous system and vision. This complex disorder is characterized by severe microcephaly, growth retardation, intellectual disability, dysmorphic features, and visual impairments. The journey to understanding, diagnosing, and using genetic testing for ARCM can be challenging but is essential in providing the best possible care and guidance for affected individuals and their families.

Understanding Autosomal Recessive Chorioretinopathy-Microcephaly Syndrome

ARCM is a genetic disorder caused by mutations in specific genes that play a crucial role in nervous system development. A recent study identified homozygous mutations in the MCM7 gene as a novel cause of this syndrome. The disorder is inherited in an autosomal recessive manner, which means that an affected individual inherits two copies of the mutated gene, one from each parent. Parents who are carriers of the mutation have a 25% chance of having a child with ARCM.

The syndrome is characterized by a combination of neurological and ophthalmological abnormalities. Affected individuals typically have severe microcephaly, which is a significantly smaller head circumference than normal. This is often accompanied by growth retardation, intellectual disability, and dysmorphic facial features. Visual impairments, such as chorioretinopathy, can also be present and can lead to progressive vision loss.

Diagnosing Autosomal Recessive Chorioretinopathy-Microcephaly Syndrome

Diagnosing ARCM can be a complex process due to the rarity of the condition and the overlapping features with other disorders. A thorough clinical evaluation, including a detailed medical history, physical examination, and imaging studies, is essential for an accurate diagnosis. A case report highlights the importance of considering ARCM in the differential diagnosis when evaluating patients with microcephaly and visual impairments.

Genetic Testing for Autosomal Recessive Chorioretinopathy-Microcephaly Syndrome

Genetic testing can be a valuable tool in confirming a diagnosis of ARCM and providing essential information for affected individuals and their families. There are several uses for genetic testing in the context of this disorder, which are discussed below.

Diagnostic Testing

Genetic testing can help confirm a diagnosis of ARCM by identifying the specific gene mutations responsible for the disorder. This can be particularly helpful in cases where the clinical presentation is ambiguous or overlaps with other conditions. Diagnostic testing typically involves sequencing the relevant genes, such as MCM7, to identify any pathogenic mutations.

Carrier Testing

Carrier testing can be performed on individuals who have a family history of ARCM or are at risk for being carriers of the mutated gene. This type of testing can help determine if a person carries one copy of the mutated gene and is at risk of having a child with the disorder. Identifying carriers can provide valuable information for family planning and genetic counseling.

Prenatal and Preimplantation Genetic Testing

For couples at risk of having a child with ARCM, prenatal genetic testing can be performed during pregnancy to determine if the fetus is affected by the disorder. This information can help families make informed decisions about their pregnancy and prepare for the potential challenges of raising a child with ARCM.

Preimplantation genetic testing can be performed during in vitro fertilization (IVF) to screen embryos for the presence of the mutated gene before implantation. This can help couples at risk for having a child with ARCM to increase their chances of having a healthy baby.

Conclusion

Autosomal recessive chorioretinopathy-microcephaly syndrome is a rare and complex disorder that affects both the nervous system and vision. Understanding, diagnosing, and using genetic testing for this condition is essential in providing the best possible care and guidance for affected individuals and their families. Advances in genetic testing have made it possible to identify carriers, confirm diagnoses, and offer prenatal and preimplantation testing options to help families navigate the challenges associated with this rare disorder.

About The Expert Reviewer

Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of  and the author of ⁠⁠Outsmart Your Genes.

Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (⁠⁠ACMG), an Associate of the American College of Preventive Medicine (⁠⁠ACPM), and a member of the National Society of Genetic Counselors (⁠NSGC)