Epileptic Encephalopathy, Early Infantile 48

Clinical Characteristics
Ocular Features: 

Poor eye contact is present from infancy.  Optic atrophy has been reported in several patients and features of retinitis pigmentosa were present in sibs of one family.

Systemic Features: 

Infants usually present with hypotonia and feeding difficulties.  Global developmental delay is also noted early and becomes more obvious with time.  Seizures are often seen early and become intractable.  Many individuals have microcephaly.  Hypermobility with dyskinesias and hyporeflexia are often present.  Speech is generally absent and many individuals are unable to sit or walk.

Brain imaging often shows atrophy of the cerebrum and cerebellum accompanied by enlarged ventricles and a thin corpus callosum.

Genetics

Homozygous or compound heterozygous mutations in the AP3B2 gene (15q25.2) can be responsible for this condition.

For another somewhat similar condition see early onset epileptic encephalopathy 28 (616211) with autosomal recessive inheritance.  For an autosomal dominant condition with a similar clinical picture, see early onset epileptic encephalopathy 47 (617166).

Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Autosomal-Recessive Mutations in AP3B2, Adaptor-Related Protein Complex 3 Beta 2 Subunit, Cause an Early-Onset Epileptic Encephalopathy with Optic Atrophy

Assoum M, Philippe C, Isidor B, Perrin L, Makrythanasis P, Sondheimer N, Paris C, Douglas J, Lesca G, Antonarakis S, Hamamy H, Jouan T, Duffourd Y, Auvin S, Saunier A, Begtrup A, Nowak C, Chatron N, Ville D, Mireskandari K, Milani P, Jonveaux P, Lemeur G, Milh M, Amamoto M, Kato M, Nakashima M, Miyake N, Matsumoto N, Masri A, Thauvin-Robinet C, Riviere JB, Faivre L, Thevenon J. Autosomal-Recessive Mutations in AP3B2, Adaptor-Related Protein Complex 3 Beta 2 Subunit, Cause an Early-Onset Epileptic Encephalopathy with Optic Atrophy. Am J Hum Genet. 2016 Dec 1;99(6):1368-1376.

PubMed ID: 
27889060

Clinical genomics expands the morbid genome of intellectual disability and offers a high diagnostic yield

Anazi S, Maddirevula S, Faqeih E, Alsedairy H, Alzahrani F, Shamseldin HE, Patel N, Hashem M, Ibrahim N, Abdulwahab F, Ewida N, Alsaif HS, Al Sharif H, Alamoudi W, Kentab A, Bashiri FA, Alnaser M, AlWadei AH, Alfadhel M, Eyaid W, Hashem A, Al Asmari A, Saleh MM, AlSaman A, Alhasan KA, Alsughayir M, Al Shammari M, Mahmoud A, Al-Hassnan ZN, Al-Husain M, Osama Khalil R, Abd El Meguid N, Masri A, Ali R, Ben-Omran T, El Fishway P, Hashish A, Ercan Sencicek A, State M, Alazami AM, Salih MA, Altassan N, Arold ST, Abouelhoda M, Wakil SM, Monies D, Shaheen R, Alkuraya FS. Clinical genomics expands the morbid genome of intellectual disability and offers a high diagnostic yield. Mol Psychiatry. 2016 Jul 19. doi: 10.1038/mp.2016.113. [Epub ahead of print].

PubMed ID: 
27431290

References

Assoum M, Philippe C, Isidor B, Perrin L, Makrythanasis P, Sondheimer N, Paris C, Douglas J, Lesca G, Antonarakis S, Hamamy H, Jouan T, Duffourd Y, Auvin S, Saunier A, Begtrup A, Nowak C, Chatron N, Ville D, Mireskandari K, Milani P, Jonveaux P, Lemeur G, Milh M, Amamoto M, Kato M, Nakashima M, Miyake N, Matsumoto N, Masri A, Thauvin-Robinet C, Riviere JB, Faivre L, Thevenon J. Autosomal-Recessive Mutations in AP3B2, Adaptor-Related Protein Complex 3 Beta 2 Subunit, Cause an Early-Onset Epileptic Encephalopathy with Optic Atrophy. Am J Hum Genet. 2016 Dec 1;99(6):1368-1376.

PubMedID: 27889060

Anazi S, Maddirevula S, Faqeih E, Alsedairy H, Alzahrani F, Shamseldin HE, Patel N, Hashem M, Ibrahim N, Abdulwahab F, Ewida N, Alsaif HS, Al Sharif H, Alamoudi W, Kentab A, Bashiri FA, Alnaser M, AlWadei AH, Alfadhel M, Eyaid W, Hashem A, Al Asmari A, Saleh MM, AlSaman A, Alhasan KA, Alsughayir M, Al Shammari M, Mahmoud A, Al-Hassnan ZN, Al-Husain M, Osama Khalil R, Abd El Meguid N, Masri A, Ali R, Ben-Omran T, El Fishway P, Hashish A, Ercan Sencicek A, State M, Alazami AM, Salih MA, Altassan N, Arold ST, Abouelhoda M, Wakil SM, Monies D, Shaheen R, Alkuraya FS. Clinical genomics expands the morbid genome of intellectual disability and offers a high diagnostic yield. Mol Psychiatry. 2016 Jul 19. doi: 10.1038/mp.2016.113. [Epub ahead of print].

PubMedID: 27431290