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Abstract We report a Japanese patient with tall stature, dolichocephaly, prominent forehead, narrow nasal ridge, mild retrognathia, subcutaneous fat reduction, bilateral entropion of both eyelids, high arched palate, long fingers, and mild hyperextensible finger joints as a case of Marfanoid-progeroid-lipodystrophy syndrome. Genetic investigation revealed a heterozygous variant NC_000015.10(NM_000138.5):c.8226+5G>A in the FBN1 gene. Skipping of exon 65 and escaping nonsense-mediated decay followed by frameshift were experimentally confirmed in the proband’s mRNA.

Coffin-Siris syndrome: New mutation implicated Genomic sequencing has revealed a new causative mutation for Coffin-Siris syndrome (CSS), a very rare disease characterized by developmental delays, intellectual disability and various anatomical abnormalities. A team from Japan led by Takanobu Otomo of Kawasaki Medical School in Kurashiki performed genetic sequencing on a young boy who showed many hallmark features of CSS. The researchers identified a previously undescribed mutation in ARID1B, a gene previously linked to the disease. The mutation introduced a premature stop signal into the ARID1B gene transcript. The boy’s cells responded to the genetic defect by activating two kinds of RNA surveillance mechanisms: one that helped eliminate the faulty transcript, and another designed to alter splicing patterns. The findings could help the medical community diagnosis other cases of CSS and ultimately find treatments.

Shwachman-Diamond syndrome (SDS; OMIM 260400) is an autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction and metaphyseal chondrodysplasia. SDS is caused by mutations in SBDS, an uncharacterized gene. A previous study in SDS patients largely of European ancestry found that most SBDS mutations occurred within a ~240-bp region of exon 2 and resulted from gene conversion due to recombination with a pseudogene, SBDSP. It is unknown, however, whether these findings are applicable to other ethnic groups. To address this question, we examined SBDS mutations in six Japanese families with SDS by direct sequencing. We identified compound heterozygous mutations in four families: two were recurrent (96?97insA, 258+2T>C), and three were novel [292?295delAAAG, (183?184TA>CT +201A>G), (141C>T+183?184TA>CT+201A>G)] mutations. Most of these mutations also appear to result from gene conversion, but the conversion events occurred at various sites between intron 1 and exon 3. Thus, gene conversion mutations in SBDS are common to different ethnic groups, but they are not confined to a limited region of the gene. [ABSTRACT FROM AUTHOR]