To determine the frequency of deletions in the PARK2 gene, Lucking et al. (1998) searched for homozygous deletions in the PARK2 gene in 12 PARK2-linked families with autosomal recessive juvenile Parkinsonism and known or suspected consanguinity (a total of 32 patients). Five of the families originated from Italy, four from France, one from the Netherlands, one from Portugal, and one from Algeria. Six of the families had previously been reported by Tassin et al. (1998). They found two novel homozygous deletions in eight patients from three families. The Algerian family carried a deletion of exons 8 and 9. Mean age at onset and clinical severity were similar in the deleted and nondeleted families. The overall clinical features were also similar with a significantly later mean age at onset than those with exon 8-9 deletions, and a trend toward greater severity for similar disease durations. The association of the exon 8-9 deletion with earlier age at onset is suggestive that the less truncated protein resulted in an additional toxic effect.

Myhre et al. (2008) investigated 11 consanguineous families with 17 affected members with recessively inherited young-onset Parkinsonism for mutations both in the parkin and PINK1 genes. In the parkin gene, a three-generation family was identified with an exon 4 deletion segregating with the disease. Both affected members were homozygous for the deletion that segregated on one haplotype that spanned the gene. Exon dosage analysis confirmed the recessive pattern of inheritance with heterozygous deletions segregating in healthy family members.

Gouider-Khouja et al. (2003) identified the genetic findings in three siblings with autosomal recessive- juvenile Parkinsonism (AR-JP) by performing a genetic linkage analysis with markers spanning the Parkin gene locus. Genotyping was determined by PCR using nine nucleotide polymorphic primers. Haplotype analysis showed homozygosity of affected individuals for three markers (D6S1550, D6S411, and D6S1599) suggesting linkage to the Park 2 locus. A recombination was observed for the fourth intragenic marker D6S305. Sequencing of the Parkin gene revealed a two-base homozygous deletion (AG) within exon 2, which allowed to classify Parkinsonism in that family as AR-JP.