Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3
The NM_001130965.3(SUN1):c.161G>A(p.Arg54His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000055 in 1,455,148 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).
SUN1 (HGNC:18587): (Sad1 and UNC84 domain containing 1) This gene is a member of the unc-84 homolog family and encodes a nuclear envelope protein with an Unc84 (SUN) domain. The protein is involved in nuclear anchorage and migration. Alternatively spliced transcript variants have been described. [provided by RefSeq, Jan 2019]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 54 of the SUN1 protein (p.Arg54His). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SUN1-related conditions. ClinVar contains an entry for this variant (Variation ID: 583170). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -