Jordan's Syndrome

Last updated
Jordan's syndrome
Other namesPPP2R5D-related intellectual disability, mental retardation, autosomal dominant 35(MRD35)
Specialty Psychiatry, pediatrics, occupational medicine, neurology, ophthalmology
Symptoms Mild to severe global developmental delay, seizure, macrocephaly, hypotonia, autism, dysmorphic facial features
DurationLifelong
CausesHeterozygous PPP2R5D mutation
Diagnostic method Molecular genetic testing
Differential diagnosis Cowden syndrome, Sotos syndrome, Smith-Kingsmore syndrome, M-CM, MPPH, 9q34 deletion syndrome, 16p11.2 deletion syndrome
Management Occupational therapy, physical therapy, speech therapy, applied behavior analysis
Frequency23 (2019) [1]

Jordan's Syndrome (JS) or PPP2R5D-related intellectual disability is a rare autosomal dominant neurodevelopmental disorder caused by de novo mutations in the PPP2R5D gene. [2] It is characterized by hypotonia, intellectual disability, and macrocephaly. [3] Children with JS may also have epilepsy or meet criteria for diagnosis with autism spectrum disorder. [4]

Contents

Signs and symptoms

Symptoms of Jordan's Syndrome (JS) are not formally defined but typically appear in early childhood and can range from mild to severe global developmental delay and intellectual disability, usually including speech delay and impairment. [5] [1] Patients with JS may meet some or all criteria for diagnosis with autism spectrum disorder due to many shared developmental symptoms. [4] Initial clinical findings may include macrocephaly, hypotonia, epilepsy, ophthalmologic abnormalities, and dysmorphic facial features. Magnetic resonance imaging may further reveal megalencephaly or defects of the ventricles or white matter. Individuals with JS may also have skeletal, cardiac, endocrine, or genital abnormalities. [1] Certain JS mutations can also cause early-onset parkinsonism between ages 20-40. [6]

Genetics

All cases of JS are caused by de novo missense point mutations in PPP2R5D , which encodes a subunit of the enzyme PP2A. At least 8 different pathogenic mutations have been identified: E197K, E198K, E200K, E420K, P201R, W207R, Q211P, and P53S. [7]

Patients are exclusively diagnosed with JS upon discovery of a pathogenic variant of PPP2R5D via genetic testing. [3] [4] As of 2019, at least 23 individuals with JS have been reported. [1]

Mechanisms

The molecular mechanisms underlying JS are unknown. Broadly, PP2A dysfunction is known to be associated with other pathologies such as Alzheimer's disease, Parkinson's disease, and cancer. [7] Studies of specific JS-causing variants such as E420K have implicated PI3K/AKT/mTOR pathway dysregulation in JS pathogenesis. [5]

Diagnosis

Jordan's Syndrome is diagnosed through molecular genetic testing, most commonly exome sequencing. [2]

Research

PPP2R5D-related intellectual disability was named "Jordan's Syndrome" after Jordan Lang, who was diagnosed by whole exome sequencing in 2014. [8] Lang's parents founded the charitable organization Jordan's Guardian Angels to connect families of individuals with JS. The foundation also funds PPP2R5D research, spanning diverse model systems from alpacas and fruit flies [9] to patient-derived induced pluripotent stem cells. [10] Ten primary investigators are affiliated with the foundation: [11]

Related Research Articles

<span class="mw-page-title-main">Fragile X syndrome</span> X-linked dominant genetic disorder

Fragile X syndrome (FXS) is a genetic disorder characterized by mild-to-moderate intellectual disability. The average IQ in males with FXS is under 55, while about two thirds of affected females are intellectually disabled. Physical features may include a long and narrow face, large ears, flexible fingers, and large testicles. About a third of those affected have features of autism such as problems with social interactions and delayed speech. Hyperactivity is common, and seizures occur in about 10%. Males are usually more affected than females.

<span class="mw-page-title-main">Megalencephaly</span> Medical condition

Megalencephaly is a growth development disorder in which the brain is abnormally large. It is characterized by a brain with an average weight that is 2.5 standard deviations above the mean of the general population. Approximately 1 out of 50 children (2%) are said to have the characteristics of megalencephaly in the general population.

Neurodevelopmental disorders are a group of disorders that affect the development of the nervous system, leading to abnormal brain function which may affect emotion, learning ability, self-control, and memory. The effects of neurodevelopmental disorders tend to last for a person's lifetime.

<span class="mw-page-title-main">HERC1</span>

Probable E3 ubiquitin-protein ligase HERC1 is an enzyme that in humans is encoded by the HERC1 gene.

<span class="mw-page-title-main">Acrocallosal syndrome</span> Medical condition

Acrocallosal syndrome is an extremely rare autosomal recessive syndrome characterized by corpus callosum agenesis, polydactyly, multiple dysmorphic features, motor and intellectual disabilities, and other symptoms. The syndrome was first described by Albert Schinzel in 1979. Mutations in KIF7 are causative for ACLS, and mutations in GLI3 are associated with a similar syndrome.

FG syndrome (FGS) is a rare genetic syndrome caused by one or more recessive genes located on the X chromosome and causing physical anomalies and developmental delays. FG syndrome was named after the first letters of the surnames of the first patients noted with the disease. First reported by American geneticists John M. Opitz and Elisabeth G. Kaveggia in 1974, its major clinical features include intellectual disability, hyperactivity, hypotonia, and a characteristic facial appearance including macrocephaly.

<span class="mw-page-title-main">Lujan–Fryns syndrome</span> Medical condition

Lujan–Fryns syndrome (LFS) is an X-linked genetic disorder that causes mild to moderate intellectual disability and features described as Marfanoid habitus, referring to a group of physical characteristics similar to those found in Marfan syndrome. These features include a tall, thin stature and long, slender limbs. LFS is also associated with psychopathology and behavioral abnormalities, and it exhibits a number of malformations affecting the brain and heart. The disorder is inherited in an X-linked dominant manner, and is attributed to a missense mutation in the MED12 gene. There is currently no treatment or therapy for the underlying MED12 malfunction, and the exact cause of the disorder remains unclear.

<span class="mw-page-title-main">Pitt–Hopkins syndrome</span> Medical condition

Pitt–Hopkins syndrome (PTHS) is a rare genetic disorder characterized by developmental delay, epilepsy, distinctive facial features, and possible intermittent hyperventilation followed by apnea. Pitt-Hopkins syndrome can be marked by intellectual disabilities as well also problems with socializing. It is part of the clinical spectrum of Rett-like syndromes.

Wendy K. Chung is an American clinical and molecular geneticist and physician. She currently directs the clinical genetics program at NewYork–Presbyterian Hospital / Columbia University Medical Center in New York City and serves as the Kennedy Family Professor of Pediatrics. She is the author of 500 peer-reviewed articles and 75 chapters and has won several awards as a physician, researcher, and professor. Chung helped to initiate a new form of newborn screening for spinal muscular atrophy which is used nationally and was among the plaintiffs in the Supreme Court case which banned gene patenting.

<span class="mw-page-title-main">KMT2E</span>

Lysine methyltransferase 2E is a protein that in humans is encoded by the KMT2E gene.

Birk-Barel syndrome is a rare genetic disorder associated with the KCNK9 gene. Signs and symptoms include mental retardation, hypotonia, hyperactivity, and syndromic facies.

SYNGAP1-related intellectual disability is a monogenetic developmental and epileptic encephalopathy that affects the central nervous system. Symptoms include intellectual disability, epilepsy, autism, sensory processing deficits, hypotonia and unstable gait.

GRIN disorders are a group of neurodevelopmental disorders that result from mutations in genes coding for subunits of an N-methyl-D-aspartate (NMDA) receptor, which leads to dysfunction of glutamate signaling. GRIN disorders are universally characterized by a varying degree of developmental delay and intellectual disability, as well as epileptic seizures. Other clinical features vary depending on the affected gene and may include muscular hypotonia, spasticity, and movement disorders. GRIN disorders are confirmed with genetic testing and managed symptomatically since there is currently no cure for the disorder.

FBXW7 neurodevelopmental syndrome is a newly discovered genetic disorder which is characterized by gastrointestinal, brain, and muscle anomalies accompanied by intellectual disabilities and developmental delays.

<span class="mw-page-title-main">HNRNPH2-related disorders</span> Medical condition

HNRNPH2-related disorder is considered as a neurodevelopmental disorder (NDD) caused by heterozygous mutation in the HNRNPH2 gene on the chromosome Xq22.

CHAMP1-associated intellectual disability syndrome, also known as autosomal dominant intellectual disability type 40 is a rare genetic disorder which is characterized by intellectual disabilities, developmental delays, facial dysmorphisms, and other anomalies.

Autosomal dominant intellectual disability-craniofacial anomalies-cardiac defects syndrome is a rare genetic disorder which is characterized by multi-systemic symptoms primarily affecting the intellect and post-natal development.

GRIN2B-related neurodevelopmental disorder is a rare neurodevelopmental disorder which is characterized by developmental delays and intellectual disabilities of variable degrees, muscle tone anomalies, feeding difficulties, and behavioral problems.

<span class="mw-page-title-main">Snijders Blok-Campeau syndrome</span> Medical condition

Snijders Blok-Campeau syndrome is a genetic disorder caused by mutations in the CHD3 gene. It is characterized by impaired intellectual development, macrocephaly, dysarthria and apraxia of speech, and certain distinctive facial features.

<span class="mw-page-title-main">Severe intellectual disability-progressive spastic diplegia syndrome</span> Medical condition

Severe intellectual disability-progressive spastic diplegia syndrome is a rare novel genetic disorder characterized by severe intellectual disabilities, ataxia, craniofacial dysmorphisms, and muscle spasticity. It is a type of autosomal dominant syndromic intellectual disability.

References

  1. 1 2 3 4 Mirzaa G, Foss K, Nattakom M, Chung WK (24 January 2019). "PPP2R5D-Related Neurodevelopmental Disorder". In Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJ, Mirzaa G (eds.). GeneReviews®. Seattle, WA: University of Washington. PMID   30676711.
  2. 1 2 "PPP2R5D-related intellectual disability". MedlinePlus. 1 February 2021. Retrieved 2021-10-01.
  3. 1 2 Yan, Lulu; Shen, Ru; Cao, Zongfu; Han, Chunxiao; Zhang, Yuxin; Liu, Yingwen; Yang, Xiangchun; Xie, Min; Li, Haibo (2021-02-12). "A Novel Missense Variant in the Gene PPP2R5D Causes a Rare Neurodevelopmental Disorder with Increased Phenotype". BioMed Research International. 2021: 1–7. doi: 10.1155/2021/6661860 . PMC   7895568 . PMID   33628804.
  4. 1 2 3 Shang, Linshan; Henderson, Lindsay B.; Cho, Megan T.; Petrey, Donald S.; Fong, Chin-To; Haude, Katrina M.; Shur, Natasha; Lundberg, Julie; Hauser, Natalie; Carmichael, Jason; Innis, Jeffrey (2016-01-01). "De novo missense variants in PPP2R5D are associated with intellectual disability, macrocephaly, hypotonia, and autism". Neurogenetics. 17 (1): 43–49. doi:10.1007/s10048-015-0466-9. ISSN   1364-6753. PMC   4765493 . PMID   26576547.
  5. 1 2 Papke, Cinta M.; Smolen, Kali A.; Swingle, Mark R.; Cressey, Lauren; Heng, Richard A.; Toporsian, Mourad; Deng, Liyong; Hagen, Jacob; Shen, Yufeng; Chung, Wendy K.; Kettenbach, Arminja N. (January 2021). "A disorder-related variant (E420K) of a PP2A-regulatory subunit (PPP2R5D) causes constitutively active AKT-mTOR signaling and uncoordinated cell growth". Journal of Biological Chemistry. 296: 100313. doi: 10.1016/j.jbc.2021.100313 . ISSN   0021-9258. PMC   7952134 . PMID   33482199.
  6. Kim CY, Wirth T, Hubsch C, Németh AH, Okur V, Anheim M, et al. (2020). "Early-Onset Parkinsonism Is a Manifestation of the PPP2R5D p.E200K Mutation". Ann Neurol. 88 (5): 1028–1033. doi:10.1002/ana.25863. PMC   9052555 . PMID   32743835. S2CID   220943402.
  7. 1 2 Biswas, Dayita; Cary, Whitney; Nolta, Jan A. (January 2020). "PPP2R5D-Related Intellectual Disability and Neurodevelopmental Delay: A Review of the Current Understanding of the Genetics and Biochemical Basis of the Disorder". International Journal of Molecular Sciences. 21 (4): 1286. doi: 10.3390/ijms21041286 . PMC   7072873 . PMID   32074998.
  8. "The History of Jordan's Syndrome". Jordan's Guardian Angels. Retrieved 2021-10-01.
  9. 1 2 Turney, Spencer (13 August 2019). "Meet the alpacas that are helping researchers who study autism, Alzheimer's and cancer". Vanderbilt University. Retrieved 2021-10-01.
  10. 1 2 3 "On a mission: $12 million state appropriation earmarked for Jordan's syndrome". 25 July 2018. Retrieved 2021-10-01.
  11. "Our Research Team". Jordan's Guardian Angels. Retrieved 2021-10-01.