query: #MPs who have a P22 (father) or P25 (mother) relationship but are missing a P40 (child) one.
  
  SELECT DISTINCT ?person1 ?person1Label ?person2 ?person2Label
  WHERE { 
   { ?person1 wdt:P31 wd:Q5 ; wdt:P39 [ wdt:P279* wd:Q16707842 ]  } 
   UNION { ?person1 wdt:P31 wd:Q5 ;  wdt:P39 [ wdt:P279* wd:Q18015642 ]  } 
   UNION { ?person1 wdt:P31 wd:Q5 ;  wdt:P39 [ wdt:P279* wd:Q18018860 ] }
    
   # person1 is an MP
   
   ?person1 wdt:P40 ?person2 .
   
   # person1 has a child
   
   MINUS { { ?person2 wdt:P22 ?person1 } UNION { ?person2 wdt:P25 ?person1 } }
   
   # but person2 does not list them as their father/mother
   
   SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
  }