diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1721c10..94e359b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -247,6 +247,15 @@
 |called_variants_nanopore       |all   |DCC added 'Is Unique' column to data model document to support validation - no impact to data submitters. |
 
 
+## 1.10 
+
+|Table            |Field           |Change notes            |
+|:----------------|:---------------|:-----------------------|
+|participant      |sex             |updated description     |
+|aligned_pac_bio  |read_length_n50 |added as optional field |
+|aligned_nanopore |read_length_n50 |added as optional field |
+
+
 ## 1.1 
 
 |Table                     |Field                      |Change notes                                                                                                                                |
diff --git a/GREGoR_data_model.json b/GREGoR_data_model.json
index 0ca04d3..e1b76c0 100644
--- a/GREGoR_data_model.json
+++ b/GREGoR_data_model.json
@@ -1,7 +1,7 @@
 {
   "name": "GREGoR Data Model",
   "description": "Data model for the GREGoR consortium",
-  "version": "1.9.2",
+  "version": "1.10",
   "tables": [
     {
       "table": "participant",
@@ -110,7 +110,7 @@
         {
           "column": "sex",
           "required": true,
-          "description": "Biological sex assigned at birth (aligned with All of Us). If individual has a known DSD / not expected sex chromosome karyotype, this can be noted in the phenotype information section.",
+          "description": "Biological sex assigned at birth (aligned with All of Us). If individual has a known DSD / not expected sex chromosome karyotype, this can be noted in the sex_detail field.",
           "data_type": "enumeration",
           "enumerations": ["Female", "Male", "Unknown"]
         },
@@ -1721,6 +1721,12 @@
           "data_type": "boolean",
           "examples": true,
           "notes": "See https://fiberseq.github.io/index.html for details on methods and Fiber-seq BAM specific tags"
+        },
+        {
+          "column": "read_length_n50",
+          "description": "N50 is the shortest read length that, when all reads are sorted by length from longest to shortest, covers 50% of the total sequence data (longer is better). Value in kilobases",
+          "data_type": "float",
+          "examples": "15"
         }
       ]
     },
@@ -2157,6 +2163,12 @@
           "data_type": "boolean",
           "examples": true,
           "notes": "See https://fiberseq.github.io/index.html for details on methods and Fiber-seq BAM specific tags"
+        },
+        {
+          "column": "read_length_n50",
+          "description": "N50 is the shortest read length that, when all reads are sorted by length from longest to shortest, covers 50% of the total sequence data (longer is better). Value in kilobases",
+          "data_type": "float",
+          "examples": "15"
         }
       ]
     },
diff --git a/sheets_to_JSON.R b/sheets_to_JSON.R
index 0e45367..8a56cb1 100644
--- a/sheets_to_JSON.R
+++ b/sheets_to_JSON.R
@@ -7,7 +7,7 @@ library(jsonlite)
 url <- "https://docs.google.com/spreadsheets/d/1p_0nhKMvKBueSrUAQMCe9cHv16WyhKSX_jnxNCuGFWg"
 model_name = "GREGoR Data Model"
 model_description = "Data model for the GREGoR consortium"
-model_version = "1.9.2"
+model_version = "1.10"
 
 # table metadata
 meta <- read_sheet(url, sheet="Table overview/status", skip=1)