Categories: DNA, Genealogy

The real gem in commercial DNA testing is the matches. Currently, AncestryDNA has by far the world’s largest bank of commercial DNA testers, with over 25 million worldwide and over 30 billion records on Ancestry from 80 countries. This combination of DNA matching and records enables testers to explore how they are related to one another (we share common ancestors with our matches), and with the records, we can confidently mount trees using primary and secondary records. No other commercial DNA testing company in the world can compare.

A few years ago, a new match from Vietnam appeared on my match list. And AncestryDNA estimated that we were 2nd to 3rd cousins, or something close to that (see Image 1 below). Second cousins share common great-grandparents, and 3rd cousins share common 2nd-great-grandparents. That’s really close.

Still, I am at least a 9th-generation Louisiana Creole on many lines, including my Landrys, Rochons, Destréhans, and others. I myself do not descend from Vietnamese. Lam’s account had no public tree for me to explore how we could be connected. I saw that Kieu Gould managed Lam’s kit, and I inboxed her to explore the connection. She told me that Lam’s father was an American and that she had narrowed Lam’s grandparents down to David Joseph Detiège and Anna Bell Parker. When I looked at the matches that Lam and I shared, I saw a small cluster of Detiège matches, who also descend from David Joseph Detiège and Anna Bell Parker. Making more sense, or so I thought.

I knew the Detiège surname well because the Detièges intermarried and intermingled with mine in St. Martinville, and I had researched long-forgotten but important Civil War veteran and Reconstruction politician and activist Émile Detiège. Émile is St. Martinville’s first and only sheriff of any measurable African descent. Dude was a big deal, but local heroes have given way to national ones in our community, so few people know anything about him or his legacy. Typical. The Detièges descend from Belgian brothers Nicolas, Édouard, and Louis Joseph Detiège from Hamme-Mille who formed relationships with Creole slave and free women of color (Roséline Dartès, Paméla-Charlotte Isidore, and Marie-Louise Fontenette).¹ Nicolas, who fathered Émile, died in 1843 while Roséline was still a slave and while their children were also still slaves.² But his brothers went on to legally marry their concubines in the same week in 1869 in St. Martinville.³ Paméla-Charlotte Isidore is from my family.⁴

Still, I myself do not descend from the Detièges. So I needed to figure out why David Joseph Detiège’s grandchildren and great-grandchildren appear in my AncestryDNA match list as close cousins. I went back and measured the distance between Lam and his 2nd great-grandparents (see Image 2 below). His great-grandfather was David Detiège, born Bernard Jefferson Davis Detiège in 1893 in St. Martinville, and his 2nd great-grandparents were Jean Ernest “Bébé” Detiège and Mary Reesey or Caissy. It’s possible that Mary was a niece of Élodie Hill, who had been a longtime close friend of my great-grandparents Télesmar Landry and May Vavasseur in St. Martinville. In fact, Élodie lived decades in and died at the home of my great-grandmother’s sister, Marie Jeanne Gladys Vavasseur and her husband Joseph Ignace Journet.⁵ So, we know these folks. Bébé was a son of Louis Joseph Detiège and Marie-Louise Fontenette.⁶

As the chart above shows, I still do not descend from this line. I went back to our shared matches to see if I could identify another cluster linking us. I found them: all on my Landry side.⁷ What in the world? On that branch, my great-grandfather was Télesmar Landry, his parents (my 2nd greats) were Alcide Landry and Félicianne Prince. None of Télesmar’s sons served in Vietnam, and his only brother Joseph Alcide Landry, had no known children and never married that we know of. The matching and relationships weren’t working on paper.

Ancestry’s new Pro Tools, a paid service, now enables Pro Tools subscribers to view how their shared matches are related to one another. As my colleague Angie Bush wrote in a recent article, this new tool is a game-changer. Simply click on one of your given matches, and view the matches you share with that match, and the relationships will now appear for Pro Tools subscribers. From this tool, I can see Lam’s paternal uncle, two aunts, first cousins, etc. who all took an AncestryDNA test and appear in our match lists. All of these matches also share descendants of Alcide Landry and his Landry siblings Louis-Victorin Landry, Aristille Landry, and Philippe Landry. This all indicates that Bébé Detiège was not Bernard Jefferson Davis Detiège’s biological father.

AUTOSOMAL DNA EVIDENCE THAT BÉBÉ DID NOT FATHER BERNARD

I know many of Bébé’s descendants, and one, Jason, kindly invited me to view his AncestryDNA match list. Jason’s great-grandfather was Jules Sidney Detiège, a son of Bébé Detiège and Mary Reesy or Caissy.⁸ Based on this relationship, if Sidney and Bernard were full brothers, then Bernard’s grandchildren (matches Marie, Emile and li2fred) would be Jason’s 2nd cousins once removed, and they’d share something like 122 cM (see Image 3). CentiMorgans are a unit to measure genetic distance between two people, or the frequency of genetic recombination.

I found Emile, Marie and li2fred (Lam’s 2 aunts and uncle) in Jason’s matches. But he shares these amounts of centiMorgans with each, and AncestryDNA‘s estimated the following relationship between them:

• Jason & Emile de Tiege: 37 cM, 4th-6th cousin.⁹
• Jason & li2fred: 66 cM, 3rd-4th cousin.¹⁰
• Jason & mdg1972: 25 cM, 4th-6th cousin.¹¹

These centiMorgans are far too low for Jason to be Marie, Emile, and li2fred’s full 2nd cousin once removed, but they fall into the average range for half-2nd cousins once removed (the average being 66 cM), based on Image 3 above. In other words, Jason and Bernard’s descendants share Mary Reesy or Caissy as a common ancestor, but not Bébé and Mary. I now needed to figure out which Landry male fathered Bernard.

FIGURING OUT WHICH LANDRY WITH AUTOSOMAL DNA

My 2nd great-grandparents were Alcide Landry and Félicianne Prince, and Lam’s 2nd greats (on paper) were Jean Ernest “Bébé” Detiège and Mary Reesy or Caissy. The matches that Lam and I share include descendants of Alcide Landry, Louis-Victorin Landry, Philippe Landry, and Aristille Landry. Alcide, Aristille, and Louis-Victorin shared the same mother (Marie Jeanne Victorine Narcisse/Le Normand), and two of them shared the same father (Charles Landry). Philippe shared the same father as Alcide and Aristille, but his mother Angélique Narcisse was Victorine’s sister. Louis-Victorin’s father was Charles’s full brother (Alexandre-Victorin Landry), and Victorine was Charles and Alexandre-Victorin’s maternal 1st cousin. This family is quite endogamous. The descendants of Louis-Victorin Landry through his “outside children” with Hélène Jean are the most numerous among the matches Lam and I share, but this is also because more of Louis-Victorin and Hélène’s descendants tested with AncestryDNA.

One of Victorine Narcisse’s sons fathered Bernard Jefferson Davis “David” Detiège, that much I am certain, because had Bernard’s Bay St. Louis, Mississippi-born wife (Marie Rita Amélie Barabino) borne David Joseph Detiège for Télesmar Landry or one of his first cousins, David’s descendants would not appear in Jason’s DNA match list at all. I went back to the match list and created a spreadsheet of the closest matches, in centiMorgans, that Lam and I share.

They include Lam’s 2 aunts and uncle mentioned above and my grandfather’s 1st cousin Iola de Blanc’s son, David McElroy. The latter David’s maternal grandmother, Marie-Thérèse Landry, was my great-grandfather Télesmar Landry’s sister.¹² So, David and I are 2nd cousins once removed, and we share 56 cM.¹³ But AncestryDNA estimates that David’s relationship to Lam’s aunts and uncle is even higher than my relationship with him, which makes sense because David McElroy is a generation closer to Télesmar Landry and Bernard Jefferson Davis “David” Detiège than I:

• David Mcelroy & mdg1972: 2nd cousins 1x removed, 126 cM.¹⁴
• David Mcelroy & li2fred: 2nd cousins 1x removed or half 2nd cousins, 130 cM.¹⁵
• David Mcelroy & Emile de Tiege: Half 3rd cousin or 3rd cousin 1x removed, 43 cM.¹⁶

Meanwhile, AncestryDNA estimates my relationship to Lam, his aunts, and uncle:

• Christophe Landry & Lam Nguyen: 3rd cousins, 100 cM.¹⁷
• Christophe Landry & mdg1972: Half 2nd cousin 1x removed or 2nd cousin 2x removed, 105 cM.¹⁸
• Christophe Landry & li2fred: Half 2nd cousin 2x removed or 3rd cousin 1x removed, 43 cM.¹⁹
• Christophe Landry & Emile de Tiege: 3rd cousin 1x removed or half 2nd cousin 2x removed, 47 cM.²⁰

Right off you should notice the siblings sharing different centiMorgans to me and to David. That’s how autosomal DNA works: its recombinant nature leaves siblings born of the exact same 2 parents inheriting different amounts of autosomal DNA from their parents.

After this, I revisited the estimated relationships between Lam, his aunts, and his uncle with Louis-Victorin Landry’s and Aristille Landry’s descendants. There is a greater centiMorgan distance between Emile, Marie and li2fred and Louis-Victorin’s descendants than between them and Alcide and Aristille’s descendants:

• A.S. [Alice Landry Shaw] & mdg1972: 3rd cousin 1x removed or half 2nd cousin 2x removed, 52 cM.²¹ Alice was Louis-Victorin Landry and Clara Rochon’s granddaughter.²²
• Agnes Donato & mdg1972: Half 3rd cousin 1x removed or 4th cousin, 23 cM.²³ Agnes is a great-granddaughter of Philippe Landry and Marie Athalie Veazey.²⁴
• Israel James Landry & mdg1972: 2nd cousin 1x removed, 119 cM.²⁵ Israel is Aristille Landry and Alice Jacquet’s great-grandson.²⁶

Alcide Landry shares the same 2 parents with Aristille Landry (Charles Landry and Victorine Narcisse). Philippe Landry was Charles’s son, but Philippe’s mother, Angélique Narcisse, was Victorine’s sister. So, Alcide and Philippe were paternal half-brothers to one another (same dad), but maternal first cousins (their mothers were sisters). Louis-Victorin Landry shared the same mother as Alcide and Aristille, but his father, Alexandre-Victorin Landry, was Charles Landry’s brother. So, Alcide and Louis-Victorin were maternal half-brothers and paternally were 1st cousins (two brothers’ sons).

But of all these shared relationships above, notice how mdg1972 (Marie Detiège)’s strongest match is with Aristille’s great-grandson, at 119 cM shared. That’s very close to Marie’s relationship with David McElroy (126 cM) and to me, sharing 105 cM.

Based on the shared centiMorgans, it looks like Bernard was either Alcide’s son (my great-great-grandfather), or Aristille Landry’s son. I went back and mapped this out in a table. If Alcide fathered Bernard, that would make Lam and I half-3rd cousins, and our shared 100 cM falls within the (high end) range for half-3rd cousins on the cM chart.

Alcide Landry and his full and half-siblings were born and reared on the east bank of Bayou Têche, down the road from St. Michael’s cemetery heading towards Loreauville in an area called Pointe-Claire. Alcide purchased land there on 23 November 1897 from Paul Chrétien, whose father and grandfather’s plantations were right next door to Alcide’s father and grandparents’ plantations.²⁷ Bébé lived on land he inherited from his father Louis Joseph Detiège, situated along St. Martin Street running to what’s now Rochon Lane, on the west bank of the Têche. So, they were not neighbors, but Bébé’s mother, Marie-Louise Fontenette, was born on a plantation neighboring Alcide and Paul’s fathers and grandfathers’ plantations.

I considered social circles, too. Alcide’s children with Félicianne Prince went to school in St. Martinville run by the Sisters of Mercy, and I suspect also at Paul Chrétien’s school. Bébé’s children went to the same schools (the only ones at the time for Nonwhites except Victor Rochon’s wife’s school on Hyacinth Street).

So, Bébé’s family and Alcide’s were not immediate neighbors, but their parents had been neighbors growing up, and their children went to the same schools. Perhaps this is how Mary Caissy came to link up with Alcide. I would need to use paternal Y-DNA testing to more definitively determine if Alcide or Aristille fathered Bernard. That’s for a later project.

– Christophe Landry

SOURCES

1. DETIEGE, Louis (d. Jean Philippe & Marie LAMBEAU)  m. 7 Dec. 1869 Louise FONTENOT (SM Ch.: v. 10, p. 132).
   
   DETIEGE, Edouard (d. Jean Philippe & Marie Josephe LAMBEAU)  m. 4 Dec. 1869 Charlotte ISIDORE (SM Ch.: v. 10, p. 126).
   
   DETIEGE, Noel of Belguim Succ. dated 11 May 1861 (SM Ct. Hse.: Succ.  # 1722). ↩︎
2. Nicolas DETIÈGE died 21 Jul 1843 at age 32 (SM Ch v 5 p 119). DETIEGE, Nicolas – a brother is Noel DETIEGE;  In Succ. dated 27  July 1843  (SM Ct. Hse.: Succ. #987). ↩︎
3. DETIEGE, Louis (d. Jean Philippe & Marie LAMBEAU)  m. 7 Dec. 1869 Louise FONTENOT (SM Ch.: v. 10, p. 132).
   
   DETIEGE, Edouard (d. Jean Philippe & Marie Josephe LAMBEAU)  m. 4 Dec. 1869 Charlotte ISIDORE (SM Ch.: v. 10, p. 126). ↩︎
4. Paméla-Charlotte Isidore’s paternal grandmother, Marguerite Orté Isaïe “Zaïre” de la Houssaye, and my 5th-great-grandmother, Charlotte de la Houssaye, were full sisters, daughters of Sorlingue and Thérèse. ↩︎
5. If Mary Reesy or Caissy is Élodie Hills’s niece, it is through Élodie’s sister, Marie Hélène Hill: DETIEGE, Ernest (d. Louis & Marie Louise FONTENOT) m. 1 March 1886 Mary RESEY (Thomas & Mayey HILLS) (SM Ch.: v. 11, p. 65 & 66). 1870 US Federal Census, St Martinsville, St Martin Parish, Louisiana, Page 9, Dwelling 54, Family 54, Lines 7-16, Jean B. Dupré household; 1880 US Federal Census, St Martinsville, St Martin Parish, Louisiana, Enumeration District 33, Page 64D, Dwelling 571, Family 571, Lines 38-42; 1900 US Federal Census, St Martinville, St Martin Parish, Louisiana, Enumeration District 71, Sheet 9B, Dwelling 154, Family 154, Lines 66-70, Pierre Journée household; 1920 US Federal Census, St Martinville, St Martin Parish, Louisiana, Enumeration District 60, Sheet 5A, Dwelling 80, Family 83, Lines 19-22, Elodie Hill household; 1940 US Federal Census, St Martinville, St Martin Parish, Louisiana, Enumeration District 50-1, Sheet 1B, 721 St Martin Street, Lines 64-70, Ignace Gournet household; all accessed on Ancestry.com. ↩︎
6. Ernest (d. Louis & Marie Louise FONTENOT) m. 1 March 1886 Mary RESEY (Thomas & Mayey HILLS) (SM Ch.: v. 11, p. 65 & 66). ↩︎
7. “AncestryDNA Matches Compare,” for Christophe Landry and Lam Nguyen, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 2nd-3rd cousins sharing 100 cM DNA, accessed July 2024. ↩︎
8. Jules Sidney DETIÈGE (Ernest & Mary REESY) was born 9 Nov 1901 (SM Ch v 14 p
   310). ↩︎
9. “AncestryDNA Matches Compare,” for Jason Reed and Emile de Tiege, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 4th-6th cousin sharing 37 cM DNA, accessed July 2024. ↩︎
10. “AncestryDNA Matches Compare,” for Jason Reed and li2fred, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 3rd-4th cousin sharing 66 cM DNA, accessed July 2024. ↩︎
11. “AncestryDNA Matches Compare,” for Jason Reed and mdg1972, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 4th-6th cousin sharing 25 cM DNA, accessed July 2024. ↩︎
12. LANDRY, John Thelisman (Alcide & Felicianne PRINCE) b. 5 Jan. 1883 (SM Ch.: v. I1-B, p. 462). LANDRY, Marie Therese (Alcide & Felicianne PRINCE) b. 10 Nov. 1880;  m. 18 Aug. 1950 James F. PIERCE at New Orleans, La. (SM Ch.: Bapt. v. 11-B, p. 406). ↩︎
13. “AncestryDNA Matches Compare,” for Christophe Landry and David Mcelroy, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 2nd cousin 1x removed sharing 56 cM DNA, accessed July 2024. ↩︎
14. Ibid., for David Mcelroy and mdg1972, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 2nd cousins 1x removed sharing 126 cM DNA, accessed July 2024. ↩︎
15. Ibid., for David Mcelroy and li2alfred, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 2nd cousins 1x removed or half 2nd cousins sharing 130 cM DNA, accessed July 2024. ↩︎
16. Ibid., for David Mcelroy and Emile de Tiege, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted Half 3rd cousin or 3rd cousin 1x removed sharing 43 cM DNA, accessed July 2024. ↩︎
17. Ibid., for Christophe Landry and Lam Nguyen, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 2nd-3rd cousins sharing 100 cM DNA, accessed July 2024. ↩︎
18. Ibid., for Christophe Landry and mdg1972, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted Half 2nd cousin 1x removed or 2nd cousin 2x removed sharing 105 cM DNA, accessed July 2024. ↩︎
19. Ibid., for Christophe Landry and li2alfred, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted Half 2nd cousin 2x removed or 3rd cousin 1x removed sharing 43 cM DNA, accessed July 2024. ↩︎
20. Ibid., for Christophe Landry and Emile de Tiege, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 3rd cousin 1x removed or half 2nd cousin 2x removed sharing 47 cM DNA, accessed July 2024. ↩︎
21. Ibid., for A.S. and mdg1972, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 3rd cousin 1x removed or half 2nd cousin 2x removed sharing 52 cM DNA, accessed July 2024. ↩︎
22. ROCHON, Clara (d. Edouard & Marie CARLIN)  m. 9 June 1875 Louis VICTORIN (Victorin & Victorine NARCISSE) (SM Ch.: v. 10, p. 289). LANDRY, Louis Luc Victoria (Louis Vitteria & Clara ROCHON) b. 6 March 1876 (SM Ch.: v. 11-B, p. 277). LANDRY, Luc (Louis & Clara NOCHON) m. 25 Jan. 1898 Rosa LORINS (Ulysse & Eleonroe WESLEY) (SM Ch.: v. 12, p.8). “U.S., Cemetery and Funeral Home Collection, 1847-Current,” Ancestry (http://www.ancestry.com), obituary of Alice Landry Shaw, dated 21 August 2021, accessed July 2024. ↩︎
23. “AncestryDNA Matches Compare,” for Agnes Donatto and mdg1972, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted Half 3rd cousin 1x removed or 4th cousin sharing 23 cM, accessed July 2024. ↩︎
24. LANDRY, Philipe (Angelique NARCISSE)  m. 3 Dec. 1877 Marie Athalie VEAZEY (Adolphe & Manette PROFIL) (SM Ch.: v. 10, # 687). LANDRY, Jeanne Agnes (Philippe & Marie VEAZEY) b. 8 Feb. 1890 (SM Ch.: v. 13, p. 124). “Texas, U.S., Select County Marriage Records, 1837-1965,” Ancestry (http://www.ancestry.com), Vincent Pratt to Agnes Landry, married 9 December 1917, in Jefferson County, accessed July 2024. “Texas, U.S., Select County Marriage Records, 1837-1965,” Ancestry (http://www.ancestry.com), Vincent Pratt to Agnes Landry, married 9 December 1917, in Jefferson County, accessed July 2024. “U.S., Newspapers.com™ Marriage Index, 1800s-current,” Ancestry (http://www.ancestry.com), Michael Joseph Donatto to Melba Rita Pratt, married 1947, in Liberty County, Texas, accessed July 2024. “Melba Rita Donatto,” obituaries, Echovita (https://www.echovita.com/), published July 2023, accessed July 2024. ↩︎
25. “AncestryDNA Matches Compare,” for Israel James Landry and mdg1972, AncestryDNA, Ancestry (https://www.ancestry.com/dna/), predicted 2nd cousin 1x removed sharing 119 cM, accessed July 2024. ↩︎
26. LANDRY, Aristide (Victorine NARCISSE)  m. 1 Feb. 1876 Alice JACQUET (Casimir & Marthe PREVOST) (SM Ch.: v. 10, # 618). LANDRY, Charles (Aristide & Alice JACQUET) b. 16 Feb. 1883 (SM Ch.: v. 11-B, p. 463). Charles LANDRY married Aldora DÉCUIR 24 May 1924 (SM Ct Hse). Charles and Aldora’s son, Camille Landry or Eulgère Joseph Landry, was Israel’s father. ↩︎
27. Paul Chrétien to Alcide Landry, land, 23 November 1897 (SM Ct Hse Conveyance Book 51 Numbers 26222 and 26225). ↩︎