Branched-chain keto acid dehydrogenase kinase deficiency

BCKDK (Branched Chain Ketoacid Dehydrogenase Kinase) deficit disease
Leucine (pictured above), Isoleucine, and valine are the branched-chain amino acids used to treat BCKDK deficit
Specialty	Medical genetics

Branched-chain keto acid dehydrogenase kinase deficiency (BCKDK deficiency) is a disease resulting from mutations of the BCKDK gene. Patients with BCKDK deficiency have low levels of branched chain amino acids (BCAA) in their organism due to accelerated breakdown of these essential amino acids. This results in delayed brain development, which may present as intellectual disability and autism spectrum disorder. Patients may suffer from epileptic seizure.

Signs and symptoms

BCKDK deficit disease symptoms may include autism, intellectual disability and developmental delay. R.Constante, Juliana et al. reported a list of symptoms in a study of 20 cases.^[1] Those symptoms included: neurodevelopmental delay, gross motor function impairment, intellectual disability, language impairment, epilepsy and clumsiness, and also microcephaly, non present at birth.^{[citation needed]}

Cause

Diagnosis

Treatment

Continuous replenishment of BCAA levels has been reported to alleviate the symptoms in patients, combined with a high protein diet. Ongoing studies, not yet published, may indicate a greater improvement if the supplementation is administrated every 3 hours. ^{[citation needed]} When treatment was applied, (supplementation of 100–260 mg/kg/day and high protein diet), all patients improved in motor functions, and half the patients reached normocephaly. None of the patients that started treatment before 2 years old developed autism, and the patient who started treatment earlier (8 months) experienced almost normal development at 3 years old.^[1][2]

Prevalence

According to Garcia-Cazorla (2020), there are currently 21 documented cases worldwide ^{[citation needed]} R.Constante, Juliana et al. reported a list of symptoms in a study of 20 cases. It was communicated in the 14th European Paediatric Neurology Society Congress .^[1] Those symptoms included: neurodevelopmental delay, gross motor function impairment, intellectual disability, language impairment, epilepsy and clumsiness, and also microcephaly, non present at birth.^{[citation needed]}

History

The disease was first described in 2012 in three unrelated families.^[3]

Later on, García-Cazorla, Oyarzabal et al.^[4] confirmed that BCKDK mutations can result in neurobehavioral deficits in humans and support the rationale for dietary intervention. In their 2013 study, they found out BCAA (leucine, isoleucine, and valine) supplementation every 5 hours plus a high protein diet showed significant improvement for BCKDK deficit disease patients.^{[citation needed]}

References

1. Constante JR, Tangeraas T, Backe PH, Mørkrid L, Oyarzábal A, Boemer F, Francois-Guillaume D, BOzturk-Hismi B, Gumus E, Al-Sannaa N, Machado I, Bueno C, Neugebauer J, Ummuhan O, Tuba E, Footitt E, Weinhold N, Artuch R, Martinez C, Tekin M, Ozturkmen-Akay H, Bacanli A, Rodríguez-Pombo P, Karaca M, García-Cazorla A (May 2022). "BCKDK deficiency: A treatable neurodevelopmental disease amenable to newborn screening" (PDF). 14th European Paediatric Neurology Society Congress: 55.
2. Trine Tangeraas, Juliana R Constante, Paul Hoff Backe, Alfonso Oyarzábal, Julia Neugebauer, Natalie Weinhold, Francois Boemer, François G Debray, Burcu Ozturk-Hism, Gumus Evren, Eminoglu F Tuba, Oncul Ummuhan, Emma Footitt, James Davison, Caroline Martinez, Clarissa Bueno, Irene Machado, Pilar Rodríguez-Pombo, Nouriya Al-Sannaa, Mariela De Los Santos, Jordi Muchart López, Hatice Ozturkmen-Akay, Meryem Karaca, Mustafa Tekin, Sonia Pajares, Aida Ormazabal, Stephanie D Stoway, Rafael Artuch, Marjorie Dixon, Lars Mørkrid, Angeles García-Cazorla, BCKDK deficiency: a treatable neurodevelopmental disease amenable to newborn screening, Brain, 2023;, awad010, https://doi.org/10.1093/brain/awad010
3. Novarino G, El-Fishawy P, Kayserili H, Meguid NA, Scott EM, Schroth J, Silhavy JL, Kara M, Khalil RO, Ben-Omran T, Ercan-Sencicek AG, Hashish AF, Sanders SJ, Gupta AR, Hashem HS, Matern D, Gabriel S, Sweetman L, Rahimi Y, Harris RA, State MW, Gleeson JG (October 2012). "Mutations in BCKD-kinase lead to a potentially treatable form of autism with epilepsy". Science. 338 (6105): 394–7. Bibcode:2012Sci...338..394N. doi:10.1126/science.1224631. PMC 3704165. PMID 22956686.
4. García-Cazorla, A.; Oyarzabal, A.; Fort, J.; Robles, C.; Castejón, E.; Ruiz-Sala, P.; Bodoy, S.; Merinero, B.; Lopez-Sala, A.; Dopazo, J.; Nunes, V.; Ugarte, M.; Artuch, R.; Palacín, M.; Rodríguez-Pombo, P.; Alcaide, P.; Navarrete, R.; Sanz, P.; Font-Llitjós, M.; Vilaseca, M. A.; Ormaizabal, A.; Pristoupilova, A.; Agulló, S. B. (2014). "Two novel mutations in the BCKDK (branched-chain keto-acid dehydrogenase kinase) gene are responsible for a neurobehavioral deficit in two pediatric unrelated patients". Wiley online library. Vol. 35, no. 4. pp. 470–477. doi:10.1002/humu.22513. PMID 24449431. Retrieved 2022-08-28.

External links

• Branched-chain keto acid dehydrogenase kinase deficiency - a record in OMIM