Tatton-Brown-Rahman syndrome

Inspired by a patient

Tatton-Brown K, Zachariou A, Loveday C, Renwick A, Mahamdallie S, Aksglaede L, Baralle D, Barge-Schaapveld D, Blyth M, Bouma M, Breckpot J, Crabb B, Dabir T, Cormier-Daire V, Fauth C, Fisher R, Gener B, Goudie D, Homfray T, Hunter M, Jorgensen A, Kant SG, Kirally-Borri C, Koolen D, Kumar A, Labilloy A, Lees M, Marcelis C, Mercer C, Mignot C, Miller K, Neas K, Newbury-Ecob R, Pilz DT, Posmyk R, Prada C, Ramsey K, Randolph LM, Selicorni A, Shears D, Suri M, Temple IK, Turnpenny P, Val Maldergem L, Varghese V, Veenstra-Knol HE, Yachelevich N, Yates

L; Clinical Assessment of the Utility of Sequencing and Evaluation as a Service (CAUSES) Research Study; Deciphering Developmental Disorders (DDD) Study, Rahman N. The Tatton-Brown-Rahman Syndrome: A clinical study of 55 individuals with de novo constitutive DNMT3A variants. Wellcome Open Res. 2018 Apr 23;3:46.

Abstract

Tatton-Brown-Rahman syndrome (TBRS; OMIM 615879), also known as the DNMT3A-overgrowth syndrome, is an overgrowth intellectual disability syndrome first described in 2014 with a report of 13 individuals with constitutive heterozygous DNMT3A variants. Here we have undertaken a detailed clinical study of 55 individuals with de novoDNMT3A variants, including the 13 previously reported individuals. An intellectual disability and overgrowth were reported in >80% of individuals with TBRS and were designated major clinical associations. Additional frequent clinical associations (reported in 20-80% individuals) included an evolving facial appearance with low-set, heavy, horizontal eyebrows and prominent upper central incisors; joint hypermobility (74%); obesity (weight ³2SD, 67%); hypotonia (54%); behavioural/psychiatric issues (most frequently autistic spectrum disorder, 51%); kyphoscoliosis (33%) and afebrile seizures (22%). One individual was diagnosed with acute myeloid leukaemia in teenage years. Based upon the results from this study, we present our current management for individuals with TBRS.

Xin B, Cruz Marino T, Szekely J, Leblanc J, Cechner K, Sency V, Wensel C, Barabas M, Therriault V, Wang H. Novel DNMT3A germline mutations are associated with inherited Tatton-Brown-Rahman syndrome. Clin Genet. 2017 Apr;91(4):623-628.

Abstract

Tatton-Brown-Rahman syndrome (TBRS) was recently described in 13 isolated cases with de novo mutations in the DNMT3A gene. This autosomal dominant condition is characterized by tall stature, intellectual disability and a distinctive facial appearance. Here, we report six cases of inherited TBRS caused by novel DNMT3A germline mutations. The affected individuals belong to two sib-ships: four from an Old Order Amish family in America and two from a French Canadian family in Canada. All of them presented with characteristic features of TBRS, including dysmorphic facial features, increased height, intellectual disability, and variable additional features. We performed clinical exome sequencing and identified two mutations in the DNMT3A gene, a c.2312G>A (p.Arg771Gln) missense mutation in the Amish family and a c.2296_2297delAA (p.Lys766Glufs*15) small deletion in the French Canadian family. Parental DNA analysis by Sanger sequencing revealed that the Amish mutation was inherited from the healthy mosaic father. This study reflects the first cases with inherited TBRS and expands the phenotypic spectrum of TBRS.