Ann Rehabil Med.  2017 Jun;41(3):505-510. 10.5535/arm.2017.41.3.505.

Identifying the KAT6B Mutation via Diagnostic Exome Sequencing to Diagnose Say-Barber-Biesecker-Young-Simpson Syndrome in Three Generations of a Family

• Kim YR
• Park JB
• Lee YJ
• Hong MJ
• Kim HT
• Kim HJ

• KMID: 2389469
• DOI: http://doi.org/10.5535/arm.2017.41.3.505

Abstract

Diagnostic exome sequencing (DES) is a powerful tool to analyze the pathogenic variants leading to development delay (DD) and intellectual disability (ID). Recently, heterozygous de novo mutation of the histone acetyltransferase encoding gene KAT6B has been recognized as causing a syndrome with congenital anomalies and intellectual disability, namely Say-Barber-Biesecker-Young-Simpson (SBBYS) syndrome. Here we report a case of SBBYS syndrome in a third generation Korean family affected with a missense mutation in KAT6B, c.2292C>T p.(His767Tyr) identified by DES. This is the first confirmed familial inherited mutation of the KAT6B reported worldwide. Our case emphasizes again the importance of basic physical examination and taking a family history. Furthermore, advances in genetic diagnostic tools are becoming key to identifying the etiology of DD and ID. This allows a physiatrist to predict the disease's clinical evolution with relative certainty, and offer an appropriate rehabilitation plan for patients.

Keyword

Say-Barber-Biesecker-Young-Simpson variant of Ohdo syndrome; Intellectual disability; KAT6B protein

MeSH Terms

Exome*
Family Characteristics*
Histone Acetyltransferases
Humans
Intellectual Disability
Mutation, Missense
Physical Examination
Rehabilitation
Histone Acetyltransferases

Figure

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  Fig. 1 Facial features of the proband (A), father (B, C), grandmother (D), uncle (E, F), and contracture deformity in metacarpophalangeal joints of father (G).

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  Fig. 2 Three generation pedigree of the patient's family. Filled symbols represent affected members, open symbols represent unaffected members. Circles and squares represent females and males, respectively.

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  Fig. 3 Sanger sequencing result of the proband, the patient's father and uncle confirms a missense mutation in KAT6B, c.2292C>T p.(His767Tyr).

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