@article {593,
	title = {Bi-allelic Variants in TONSL Cause SPONASTRIME Dysplasia and a Spectrum of Skeletal Dysplasia Phenotypes.},
	journal = {Am J Hum Genet},
	volume = {104},
	year = {2019},
	month = {2019 03 07},
	pages = {422-438},
	abstract = {<p>SPONASTRIME dysplasia is an autosomal-recessive spondyloepimetaphyseal dysplasia characterized by spine (spondylar) abnormalities, midface hypoplasia with a depressed nasal bridge, metaphyseal striations, and disproportionate short stature. Scoliosis, coxa vara, childhood cataracts, short dental roots, and hypogammaglobulinemia have also been reported in this disorder. Although an autosomal-recessive~inheritance pattern has been hypothesized, pathogenic variants in a specific gene have not been discovered in individuals with SPONASTRIME dysplasia. Here, we identified bi-allelic variants in TONSL, which encodes the Tonsoku-like DNA repair protein, in nine subjects (from eight families) with SPONASTRIME dysplasia, and four subjects (from three families) with short stature of varied severity and spondylometaphyseal dysplasia with or without immunologic and hematologic abnormalities, but no definitive metaphyseal striations at diagnosis. The finding of early embryonic lethality in a Tonsl murine model and the discovery of reduced length, spinal abnormalities, reduced numbers of neutrophils, and early lethality in a tonsl zebrafish model both support the hypomorphic nature of the identified TONSL variants. Moreover, functional studies revealed increased amounts of spontaneous replication fork stalling and chromosomal aberrations, as well as fewer camptothecin (CPT)-induced RAD51 foci in subject-derived cell lines. Importantly, these cellular defects were rescued upon re-expression of wild-type (WT) TONSL; this rescue is consistent with the hypothesis that hypomorphic TONSL variants are pathogenic. Overall, our studies in humans, mice, zebrafish, and subject-derived cell lines confirm that pathogenic variants in TONSL impair DNA replication and homologous recombination-dependent repair processes, and they lead to a spectrum of skeletal dysplasia phenotypes with numerous extra-skeletal manifestations.</p>},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2019.01.007},
	author = {Burrage, Lindsay C and Reynolds, John J and Baratang, Nissan Vida and Phillips, Jennifer B and Wegner, Jeremy and McFarquhar, Ashley and Higgs, Martin R and Christiansen, Audrey E and Lanza, Denise G and Seavitt, John R and Jain, Mahim and Li, Xiaohui and Parry, David A and Raman, Vandana and Chitayat, David and Chinn, Ivan K and Bertuch, Alison A and Karaviti, Lefkothea and Schlesinger, Alan E and Earl, Dawn and Bamshad, Michael and Savarirayan, Ravi and Doddapaneni, Harsha and Muzny, Donna and Jhangiani, Shalini N and Eng, Christine M and Gibbs, Richard A and Bi, Weimin and Emrick, Lisa and Rosenfeld, Jill A and Postlethwait, John and Westerfield, Monte and Dickinson, Mary E and Beaudet, Arthur L and Ranza, Emmanuelle and Huber, Celine and Cormier-Daire, Val{\'e}rie and Shen, Wei and Mao, Rong and Heaney, Jason D and Orange, Jordan S and Bertola, D{\'e}bora and Yamamoto, Guilherme L and Baratela, Wagner A R and Butler, Merlin G and Ali, Asim and Adeli, Mehdi and Cohn, Daniel H and Krakow, Deborah and Jackson, Andrew P and Lees, Melissa and Offiah, Amaka C and Carlston, Colleen M and Carey, John C and Stewart, Grant S and Bacino, Carlos A and Campeau, Philippe M and Lee, Brendan}
}
@article {657,
	title = {GGC Repeat Expansion and Exon 1 Methylation of XYLT1 Is a Common Pathogenic Variant in Baratela-Scott Syndrome.},
	journal = {Am J Hum Genet},
	volume = {104},
	year = {2019},
	month = {2019 Jan 03},
	pages = {35-44},
	abstract = {<p>Baratela-Scott syndrome (BSS) is a rare, autosomal-recessive disorder characterized by short stature, facial dysmorphisms, developmental delay, and skeletal dysplasia caused by pathogenic variants in XYLT1. We report clinical and molecular investigation of 10 families (12 individuals) with BSS. Standard sequencing methods identified biallelic pathogenic variants in XYLT1 in only two families. Of the remaining cohort, two probands had no variants and six probands had only a single variant, including four with a heterozygous 3.1 Mb 16p13 deletion encompassing XYLT1 and two with a heterozygous truncating variant. Bisulfite sequencing revealed aberrant hypermethylation in exon 1 of XYLT1, always in trans with the sequence variant or deletion when present; both alleles were methylated in those with no identified variant. Expression of the methylated XYLT1 allele was severely reduced in fibroblasts from two probands. Southern blot studies combined with repeat expansion analysis of genome sequence data showed that the hypermethylation is associated with expansion of a GGC repeat in the XYLT1 promoter region that is not present in the reference genome, confirming that BSS is a trinucleotide repeat expansion disorder. The hypermethylated allele accounts for 50\% of disease alleles in our cohort and is not present in 130 control subjects. Our study highlights the importance of investigating non-sequence-based alterations, including epigenetic changes, to identify the missing heritability in genetic disorders.</p>},
	issn = {1537-6605},
	doi = {10.1016/j.ajhg.2018.11.005},
	author = {LaCroix, Amy J and Stabley, Deborah and Sahraoui, Rebecca and Adam, Margaret P and Mehaffey, Michele and Kernan, Kelly and Myers, Candace T and Fagerstrom, Carrie and Anadiotis, George and Akkari, Yassmine M and Robbins, Katherine M and Gripp, Karen W and Baratela, Wagner A R and Bober, Michael B and Duker, Angela L and Doherty, Dan and Dempsey, Jennifer C and Miller, Daniel G and Kircher, Martin and Bamshad, Michael J and Nickerson, Deborah A and Mefford, Heather C and Sol-Church, Katia}
}
