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The HNRNP-RNDDs are distinct disorders with overlapping clinical traits.

We are an umbrella organization to cover all of the HNRNP-RNDDs. As they have similar mechanisms of disease, it is likely that there are shared therapeutic strategies to uncover.

Fast Facts

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Digital World Map

At least
~1 in 22,620 individuals have an

There are at least 10 HNRNP-RNDDs, and that number is growing

Individually, each HNRNP-RNDD is ultra rare but together they overcome their ultra rare status

Rare Disease: a disease that is diagnosed in less than 200,000 individuals in the US, or less than
1 in 1000 individuals

Ultra-rare Disease: a disease that is diagnosed in less than 1 in 50,000 individuals




have developmental delay

intellectual disability



have speech and language delay and/or difficulties



have seizures



have motor skills delay



have behavioral differences, including autism spectrum disorder, ADHD, and anxiety



have differences in brain structure



have hypotonia



have skeletal differences such as scoliosis and hand/feet anomalies



have vision and/or eye problems



have distinct facial features, although they vary by HNRNP-RNDD

This data is from Gillentine et al., 2021 and the continuation of that study

Individual HNRNP-RNDDs

The HNRNP-RNDDs are related but distinct disorders. We have color coded them by which are more related to each other.

Heres what we know is different


HNRNPC-RNDD is one of the newest HNRNP-RNDDs described. 

  • Most individuals with HNRNPC-RNDD have a happy demeanor


HNRNPD-RNDD has only been described in one paper.

  • Speech is particularly affected

  • Behavioral differences such as autism spectrum disorder are common

  • Differences in movement (ataxia, poor coodination, dystonia) have been observed


hnRNPG variants result in Shashi-related intellectual disability, which has only been described in a few families. The disorder is X-linked and only affects males (who have one copy of the X chromosome).

  • Many have short stature 

  • Hearing is often affected

  • There are shared differences in facial features


HNRNPH1-RNDD has multiple papers published on it. 

  • Growth delay is common

  • Speech is particularly affected

  • MRI abnormalities are common

  • Vision and eye issues are common

  • Differences in facial features are common


HNRNPH2-RNDD is also known as Bain-type intellectual disability. Mostly girls are affected, but a small number of boys have been reported. 

  • Many individuals have genetic variants that impact the same part of the protein

  • Growth delay is observed in many individuals

  • Speech and motor skills are significantly affected

  • Behavioral differences are common, including autism spectrum disorder, anxiety, and hyperacusis

  • Vision issues are common

  • There are consistent facial features


Variants in HNRNPK cause Au-Kline Syndrome. 

  • There are distinct facial features observed in many individuals with Au-Kline Syndrome.

  • Skeletal differences, including scoliosis, are common

  • ~20% of cases have craniosynostosis

  • Congenital hip dysplasia is common

  • Many individuals have heart issues


HNRNPR-RNDD has been in two publications.

  • Many individuals have growth delay

  • Many have behavioral differences, such as autism spectrum disorder and attention deficit hyperactivity disorder

  • Skeletal differences have been reported, such as scoliosis or hand and feet differences such as clinodactyly

  • There are not specific facial features, but many individual have differences in ear structure, and microcephaly is common

  • Cardiac issues are reported in half of cases


HNRNPQ/SYNCRIP-RNDD has been in multiple publications. 

  • Most individuals have speech and/or language delay, and many are nonverbal

  • Behavioral differences such as autism spectrum disorder are common


HNRNPU-RNDD is fairly well characterized, with several publications. 

  • Seizures are reported in almost all cases

  • Speech and language delay is common


HNRNPUL2-RNDD has only one publication. 

  • Growth delay is common

  • Both speech and motor skills are delayed

  • Behavioral differences such as autism spectrum disorder and ADHD are common

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